Company Extends Alkaline Battery Life With Voltage Booster

New submitter ttsai writes: Batteroo is a Silicon Valley company preparing to release its Batteriser product in September. The Batteriser is a small sleeve that fits around alkaline batteries to boost the voltage to 1.5V. This means that batteries that would otherwise be thrown into the trash when the voltage dips to 1.3V or 1.4V could be used until the unboosted voltage reaches 0.6V, extending the useful life of a battery 8x, according to the company. This product has the potential to reduce the number of batteries in landfills as well as increasing the time between replacing batteries. The expected price of the sleeve is $10 for a pack of 4 sleeves.

Comments

If it sounds too good to be true

[Anonymous Coward]

It probably is.

Re:If it sounds too good to be true

[Megane]

And there's math behind it, too. To raise the volts, you have to lower the amps. It'll work until it can't provide enough current for the device that it's powering. The form factor is the tricky part, because you need to fit a boost coil and a capacitor in there somehow, and they might have to custom-wind the coil to make it fit, making it more costly to manufacture than it would be with off-the-shelf parts.

It would also have to know when the device is turned off. I think the Joule Thief design puts its power switch before the boost converter. You can't do that when wrapped around a single cell.

Another "too good too be true" is if you have a "pipe"-style battery compartment and the batteries leak, it could be harder to extract them. Tray-style battery compartments should be no problem.

But if they really work like they ought to work, I want some. Even if it's only a 2x lifetime, I want to use them in an IR remote control. One big problem with IR remotes is as the batteries get weaker, contact resistance becomes a problem. You can make batteries last longer by rotating them in place a little, which I guess cleans the contacts a tiny bit. Just boosting the voltage should help things right there.

Re:If it sounds too good to be true

[dgatwood]

Also why would anyone make a bluetooth keyboard without a proper boost converter that can run down to the alkalines minimum voltage!!!

Because the device can't tell whether you're using an alkaline battery or not, and if you run a rechargeable battery down to an alkaline battery's minimal voltage, you'll permanently damage the battery.

Re:If it sounds too good to be true

[quenda]

The deceit is obvious if you look at the discharge curve.
Yes, if you throw it away at 1.4V under load, most of the capacity remains. But it is bullshit because nobody does that.
High-drain devices will cope with much lower voltage, and low drain devices (like remote controls) will almost completely deplete the battery before you notice a drop in effectiveness.
For real high-drain devices like cameras, most people use NiMH, which has a nominal 1.2V only.

Re:If it sounds too good to be true

[mc6809e]

The problem is that many devices require ridiculously high minimum threshold voltages just to work.

TI, for example, sells a remote control IR encoder that requires a supply voltage of 2.7V. That means two AA batteries in series run down to below 1.35V apiece will not run a device with that IR encoder.

A typical AA battery will deliver only about 0.40 AH before it runs down to 1.35V. That 0.40 AH is of a 2.1 AH total. That's a huge waste.

Re:If it sounds too good to be true

[Brett Buck]

And there's math behind it, too. To raise the volts, you have to lower the amps. It'll work until it can't provide enough current for the device that it's powering.

      If it holds a constant 1.5V output the current draw from the device will also remain constant. What *will* happens is that as the battery terminal voltage (input to the boost converter) drops, the current drawn from the battery will go up, not down. It effectively turns the load into a constant power device.
      I am skeptical about the life-saving claims. Alkaline battery-power devices are typically expected to operate down to about 1V terminal voltage. Since the primary effect of discharging is ion depletion, the internal resistance of the battery is what is changing, meaning by the time you get to doubling the current at low states of charge, you will be depleting it much faster. So the time of use will fall off a cliff very abruptly at the end.

Re:If it sounds too good to be true

[Anonymous Coward]

I get a bit more mileage out of batteries by starting them off in a higher demand item (like an XBox controller) and when the battery is no longer powerful enough for that, I put it in a bin to be used for TV remotes.

Re:If it sounds too good to be true

[AmiMoJo]

This will be totally unsuitable for remote controls and will dramatically reduce the life of batteries used in them. Remote controls spend most of their time idle, drawing only a microampere or two from the batteries. Unless you intend to physically switch these cells on/off every time you want to use the remote...

Quality remotes have their own boost circuits to do this kind of thing, controlled by a microcontroller that turns them on when you press a button. Most are designed to work down to at least 1V, if not 0.9V. The 1.4V figure from TFA is nonsense; NiMH cells start at 1.2V when fully charged.

This is the wrong solution. The boost circuit needs to be part of the device, not part of the battery.

Re:If it sounds too good to be true

[RabidReindeer]

Actually, that has been my experience.

For a long period of time, batteries seemed to be pretty clean. In the past few years, however, I've seen a lot of leaky batteries. Not so much C and D cells, but AA's and disc batteries - some of which have leaked in the original packaging.

In fact, it's been fairly common for me to discover that a device that was still functioning was also corroding the battery compartment.

Re:If it sounds too good to be true

[Mal-2]

Nah...

It also works on NiMH batteries (1.2V.)

Excellent. I like Eneloop NiMH quite a bit, but my camera doesn't. It's very voltage-picky. In fact, its voltage requirement for the adapter is 3.7V, even though it's a 2xAA device. Needless to say, it reports "low battery" from the very first moment with NiMH -- and then runs for many hours flashing that warning. The problem is that I get no warning when it really is about to keel over, and that this happens only about 50% of the way through the charge.

The reason we use Alkaline batteries is for the long shelf life, not the use life.

Eneloops again. They'll hold most of their charge for months, and are shipped ready to use. Now with this fixing the voltage disparity, there's even less reason to avoid rechargables.

Re:If it sounds too good to be true

[140Mandak262Jamuna]

Depends on the device that is paired with the remote. The set top boxes made by near monopolies of Fisher Scientific and its compatriots have no real competition and they ship crappy remotes designed back in 1970 because ... because they can. What's the user gonna do? Most remotes made by global brands that sell in third world countries have very strong voltage regulation of their main products and very good remotes that work with dead batteries. Indian local language magazines will routinely report, "If you leave your batteries in direct sun light for 8 hours, your remote will work for one more year!"

Re:If it sounds too good to be true

[fraxinus-tree]

Yep. It IS too good to be true.

(1) an adequate electric device will drain a cell down to 0.9-0.8v. For a good 1.5v alkaline cell this is about 80% of the energy at all possible. Further, the internal resistance limits kick in. For a good 1.2v NiMH at 0.9v you are at 95%-or-something-like mark. Not much to save by draining more. "Salt" batteries leak electrolyte when drained too low.
(2) booster efficiency. 'nuf said. Space constraints and the very small coil don't help either.
(3) idle consumption = ?
Generally, you can get at most 20% more on alkaline batteries in a very limited cases. In most cases, you'll get less or much less.

Re:If it sounds too good to be true

[Hodr]

I feel like the best application, if this works as promised, is to raise NIMH cells from 1.2v to 1.5v. Sure, they work just fine in most applications, but for some they are borderline or don't work at all. I'm thinking specifically of my camera that will only work with Alkaline or NiCad.

Re:If it sounds too good to be true

[Anonymous Coward]

That's the thing - they aren't "bad" per se. They are just not powerful enough for an XBox controller. They work fine in a TV remote.

Re:If it sounds too good to be true

[BitZtream]

If you're trying to use 2 AA batteries to power a 2.7v device, you're just stupid. You don't get to blame the semiconductor company and the laws of physics for your inability to make a design that functions.

Rechargable AA cells NEVER REACH 1.35v to start with.

You're essentially bitching about the fact that you under power the device because of a bad design.

Or use the 1.8v version of the device.

Re:If it sounds too good to be true

[fizzer06]

You don't need a coil to boost the voltage. I've done it with an oscillator, diodes and capacitors.

Re:If it sounds too good to be true

[fgouget]

I just don't see this as being a common problem: all 20 devices I have work just fine with NiMH batteries that only supply 1.2V.

Re:If it sounds too good to be true

[jiriw]

NiCd starts at 1.2V. But nobody (should be) use(ing) those any-more. My experience is that most good NiMH cells start at 1.4-1.5V and maintain 1.25V during most of their in-use-time.

It shouldn't be too hard to switch on the boost circuit this Batteriser supposedly has, only when a reasonable current is drawn by the device. A current sensing circuit should not add that many components. That should prevent the Batteriser from drawing power to keep the boost circuit running when the device is switched off...

[edit]
-Unfortunately I'm unable to show you the ASCII art I had made... So here is a description of it:
Main circuit, in series: +bat --[>|-- [R2] - device - -bat (ground).
Booster circuit, 4 leads: on both sides of the diode, ground and Current detection sense input.
Current detection circuit, 3 leads: on both sides of R2 and Current detection sense output.
[/edit]

Something like this (just a rough idea. I'm a radio amateur, not an electronics engineer): R2 is very small and in series with the device (and the battery). Current is sensed over R2. A diode (pref. a low drop one) maintains most of the original battery voltage over device as long as little current is drawn. When boost circuit kicks in, voltage is boosted, the diode prevents the surplus voltage from running back to the input of the boost circuit. Drawback, R2 will dissipate some energy and its resistance depends on how sensitive you can make your current detection circuit. Also, the current detection circuit itself may use some energy but if devices with a 'soft' standby can be battery powered and drain the battery in a matter of multiple years instead of days (I'm looking at calculators and those small bike LED-lights), so can this Batteriser.

There is only one sort of device I can think of which may not be able to deal with this. I know some devices that have a stand-by current in the micro-ampere range that still do need a rather high supply voltage, else they reset, restart, draw lots of current while restarting and then go back into stand-by. If the booster circuit shuts down while they are in standby, it would mean and endless cycle of restarts, draining the battery even faster. Of course those devices already would drain the battery faster in the original situation. When the battery voltage would become low the first time, the device resets. Then because of the internal resistance of the battery, the voltage would drop even more by the current drawn by the start-up sequence.... resulting in a reset ... rinse and repeat. A boost circuit should have a capacitor at the device side of things (if only to smooth out the high frequency noise from the boosting). If you can make it rather large (in capacity) and have a voltage sense circuit over it that turns on the boost circuit on for a bit if the voltage drops under, let's say 1.4 volt, maybe you can remedy that problem. But how much room is there for a supercap in such a small device as the Batteriser?

Re:If it sounds too good to be true

[NixieBunny]

Exactly! This guy's hoping to make money fixing stupid devices. It's just rewarding the companies who make the stupid devices.

Re:If it sounds too good to be true

[Darinbob]

I also think many devices using small batteries are also relatively simple as well as miniaturized, like the remote controller or bluetooth mouse. It's extra design and cost to insert a boost into the circuit. So you get the engineering tradeoff here; the cheapest solution to the problem if you look at only device cost by itself is to assume that the customers will change their batteries every 6 months.

Re:If it sounds too good to be true

[toddestan]

Alkaline batteries used to contain significant amounts of mercury in them which is why they wanted them recycled. Around the late 90's, they managed to remove almost all of the mercury, so now in many places it's considered acceptable to throw them away (but not all places, California still considers them hazardous waste). There really isn't anything in them that's terribly valuable so there's little interest in recycling them to recover the raw materials. So into the landfill they go.

Re:If it sounds too good to be true

[Agripa]

The TI-30 and similar calculators used a 9 volt battery but had rechargeable battery modules which could be used as well that operated like this. Inside was a NiCd battery and boost converter which always ran producing the 9 volts that the calculator expected. Operating life was good even though the boost converter never shut off. Today we could do much better.

http://www.datamath.org/BP_Rep...

Re:If it sounds too good to be true

[Agripa]

A burst mode or hysteretic converter can have very low (in the microamp range) quiescent current draw. At low or no output current, they spend most of their time shut down with only the comparator and reference active.

Too good to be true

[brausch]

The article presents some info that just isn't quite right. The device will probably be useful but not nearly as good as they claim. Instead of 8 or more to one times the typical battery lifetime, it will be more like two times. Google "joule thief" and read the articles and comments carefully. This device works the same way; just in a compact package.

Re:Too good to be true

[brausch]

There are lots of good comments posted after the original article.

Re:Too good to be true

[gweihir]

My intuition as well. In fact, when looking at discharge curves for alkaline batteries and assume than any reasonable gadget will use them down to something like 1.15V (otherwise it does not work with NiMH accumulators which only have 1.22V when fully charged), I expect that you will get less than an 80% boost. That is a bit different from the claimed 500% to 800% and explains why the battery industry does not care much. (Discharge curve e.g. here: http://www.stefanv.com/electro...)

Of course a device with brain-dead power engineering that claims that batteries are dead at 1.4V would get something like an 1000% boost, but such a device is broken by design and also does not work with accumulators in the first place. Also note that if said device is an LED flashlight with step-up regulator (single-cell ones all are), it already does what this thing is claiming to do.

The break-in story adds to my impression that this is nowhere near as good as claimed.

Re:Too good to be true

[msauve]

But the claim was "batteries that would otherwise be thrown into the trash when the voltage dips to 1.3V or 1.4V."

One doesn't have to look hard to find that an alkaline cell drops to 1.4 V when only about 10% of its energy capacity is used. So I can believe the claim, even though it's exceedingly misleading. I can't think of a device designed for alkaline batteries which would fail to work at even 1.0 V/cell.

From the article: "Batteroo is a Silicon Valley company preparing to release its Batteriser product in September."

And don't forget, it's Batterrific!

Re:Too good to be true

[skids]

There are actually poorly engineered adgets out there that cut off well before an alkaline is tapped. They are the same ones that have trouble operating off NiMHs.

(Whereas the ones the SP mentions that drain the hell out of batteries need to be used with care with NiMH as they can decrease rechargeable shelf life by doing that.)

Ever since LSD NiMHs hit the market I have not bought a single alkaline oter than to put in gifts given to someone who can't handle rechargeables.

Re:Too good to be true

[Bite The Pillow]

When my beard trimmers, yes that's a thing, from 1998, go dead (3 AA), or my elliptical from 2004 (4 D), or any number of remote controls for my DVD, Xbox, roku, tv, or receiver, die, and I have to rotate batteries to charge them, I would prefer to eke a few more minutes with this.

Alternatively, a charge level indicator so I know going in if I need to rotate and charge.

Build this into devices, switching when the battery dies, would be cool, but additional drain like a charge indicator.

As a guy with batteries, nothing so far has dissuaded me.

I, in contrast with most people, will not be buying the first 6 months. So plenty of time for real measurements before I decide.

Re:Too good to be true

[tlhIngan]

My intuition as well. In fact, when looking at discharge curves for alkaline batteries and assume than any reasonable gadget will use them down to something like 1.15V (otherwise it does not work with NiMH accumulators which only have 1.22V when fully charged), I expect that you will get less than an 80% boost. That is a bit different from the claimed 500% to 800% and explains why the battery industry does not care much.

Of course a device with brain-dead power engineering that claims that batteries are dead at 1.4V would get something like an 1000% boost, but such a device is broken by design and also does not work with accumulators in the first place. Also note that if said device is an LED flashlight with step-up regulator (single-cell ones all are), it already does what this thing is claiming to do.

Actually, if you look at battery datasheets, if you cut off at 0.9V per cell, you have basically gotten around 95% of the energy out of it.

The problem is, most devices don't go down to 0.9V - they cut out at 1.1V or higher and you've just thrown away about 50% of the cell. If you cut out higher than that, you're throwing away perfectly good batteries.

So no, this thing doesn't do any magic, other than letting you extract more out of your battery because most devices are pure crap and they cut out way too early. Depending on how crappy the design, it could give you easily double the battery life.

Designing for batteries is hard - even alkalines tend to be 1.5V, then drop to 1.2V within a few % of use, then basically linearly drop from there to 0.8V or so at which point you're at 99% extraction. But that's a huge range of voltages - from 1.5V to 0.9V per cell. If you use two batteries in series and use a LDO to power your 1.8V processor, that LDO will cut out at around 2V or so, or 1V/cell, which still gets you only 75% of capacity or so. Use a lamer LDO and you can easily cut out at 1.1V a cell or more and waste so much battery.

Re:Too good to be true

[dougmc]

otherwise it does not work with NiMH accumulators which only have 1.22V when fully charged

No, NiMH and NiCD cells are at 1.41 volts when fully charged. By the time they hit 1.22 volts, perhaps 60% of the energy that was in the battery is gone.

I do not know why primary cell voltages are given at their very highest possible voltage and secondary cell voltages are given approximately at the middle of their useful range -- it basically turns the "1.5v vs 1.2v" thing into an apples to orange comparison, when saying "1.5v vs 1.4v" would be far more accurate.

That said ... how useful this device would be would depend on the application. If a device will stop working when the battery gets down to 1.3 volts ... yes, this device could help a lot, especially with NiMH cells that start at 1.4 volts rather than alkaline's 1.5 volts. But that's a poorly designed device that will leave a lot of battery power unused.

But, if the device will work until the battery gets down to 0.9 volts ... there's not much energy left, and this device can not possibly help much.

Re:Too good to be true

[rot26]

+1 virtual mod point for you. (Best I can do atm, sorry.)

Re:Too good to be true

[chihowa]

I do not know why primary cell voltages are given at their very highest possible voltage and secondary cell voltages are given approximately at the middle of their useful range -- it basically turns the "1.5v vs 1.2v" thing into an apples to orange comparison, when saying "1.5v vs 1.4v" would be far more accurate.

The different chemistries are described this way because of the characteristics of the discharge curves. As you can see here, the NiMH battery (and NiCd is similar) spends most of its life at 1.2V, while the ZnMnO2 batteries have no such plateau.

Under any considerable load, both battery types will drop from 1.5V/1.4V very quickly, so measuring 1.2V across a loaded NiMH battery doesn't mean that 60% of the energy is gone. Self-discharge alone will drop most NiMH/NiCd cells to below 1.4V pretty quickly.

Re:Too good to be true

[Darinbob]

I noticed my Roku remote controller burns through batteries much faster than a typical remote. Ie, 6 months versus several years. I think this is either because it's active much more often (it has a radio link active even when no button is pushed), or because it has a higher voltage requirement on some of the parts inside. I think this sort of boost would work here because these batteries do start working again if I jiggle or rotate them.

I think the use here depends upon the type of device. Note that the demo in the article used an Apple bluetooth trackpad which seems like the sort of thing to have parts with a higher voltage threshold.

Re:Too good to be true

[dougmc]

That discharge curve you posted lacks context. What's the discharge rate? What battery?

And unfortunately, the source page does not provide these details either, basically making the chart useless. In fact, I suspect that the author just drew it freehand rather than actually measuring it? Certainly, his starting voltage is flat out *wrong* and his curve seems too flat. (In fact, he has the NiMH voltage *increasing* slightly during parts of the discharge period!)

Here's a better reference, with a much more useful discharge curve on page six. This is for a specific battery (Energizer NiMH NH15 AA) at a specific discharge rate (750 mA with a pulse (presumably the pulse is to remove the effect of the internal resistance when measuring and to simulate a low discharge rate -- which I would call slightly misleading, but they did disclose it.) Note the starting voltage of a bit over 1.4 volts, and note that once the battery hits 1.2 volts ... it is indeed about halfway discharged.

If you'd like to see a bunch more *real world* NiMH discharge curves, here you go. Keep in mind that they're not all for a single cell, but those that are start at a bit over 1.4 volts for lower discharge rates and a bit under 1.4 volts for higher discharge rates. And here's the alkaline discharge curves to compare to.

Self-discharge alone will drop most NiMH/NiCd cells to below 1.4V pretty quickly.

They do have a significant self discharge rate -- but still, they start at 1.41 volts, not 1.22 volts. And the low-discharge rate NiMH cells (like the Eneloops) have *greatly* reduced the self discharge rate.

Either way, if you were trying to explain why primary batteries are rated based on their starting voltages and primary batteries on their "middle of their discharge curve" voltages ... you didn't really succeed. The real world discharge curves for NiMH and alkaline batteries look pretty similar, but why should we look at the very highest point for alkalines and the middle point for NiMH beyond "that's the way it's always been done" ?

Re:Too good to be true

[gweihir]

As you get no switch and no warning, you would have to remove the batteries, add this device and then put them in again. That is a lot of effort. Probably better and cheaper to just get a spare set of alkaline batteries to be used for those 2-3 minutes only.

Re:Too good to be true

[gweihir]

I am not taking exception with this type of power engineering being useful. I am taking exceptions with the claims of 500-800% more use you supposedly get. That is deep in the area of a direct lie.

Re:Too good to be true

[gweihir]

Your numbers are way off. Maybe get a new voltmeter?

Re:Too good to be true

[gweihir]

Even the figure you quote says that a NiHM is down to about 1.25V before 20% discharge. You pulled your number of 1.22V at 60% discharge right out of your backside.

Re:Too good to be true

[gweihir]

You really do not understand step-up regulation and in particular fly-back topology. Stop posting bullshit.

Re:Too good to be true

[gweihir]

If "jiggle or rotate" works, then you have a contact problem, not a battery voltage problem. The Apple BT track-pad was likely selected as one particularly badly designed device (Apple engineering frequently sucks badly, but many people do not know that or are in denial) that can demonstrate the effect.

Re:Too good to be true

[dougmc]

Looking at the discharge curve given in the Energizer pdf, page 6, for NiMH NH15 AA battery being discharged at 750 mA with 10 mA pulses ... the battery finally hits 1.2 volts right at about 60% discharge at the 750 mA discharge rate, and about 1.22 volts during the 10 mA "pulses".

The exact voltages depend on discharge rate -- higher discharge rates give you a lower voltage, but at a low discharge rate (around a C/20 discharge rate), the battery hitting 1.22 volts when 60% discharged is approximately what that charge shows. And even at a higher rate -- C/3 -- it finally hits 1.20 volts when about 60% discharge.

And yet the discharge curve that chihowa linked to had the NiMH cell *starting* at about 1.24 volts, then going down to 1.2 volts, then *going up slightly* before going down again -- *THAT* is pulling it out of your backside.

I linked to dozens of discharge curves, done at various rates with various batteries, but in general you'll find that when the cell finally hits 1.20 volts, it's roughly 50% discharged, with the exact voltages and discharge amounts depending on the discharge rate and the exact battery involved.

For example, looking at this specific one -- looking at the 0.2C discharge curve (0.2C means that the battery is fully discharged in five hours), when the battery is 60% discharge thed voltage is about 1.23 volts.

Re:Too good to be true

[gweihir]

Seriously, there are always some circumstances where even the most bizarre claims are true. The question is whether they matter. I actually stopped thinking about it when you made the bizarre claim that NiCd and NiMH behave the same.

Or in other words, you may be technically correct in some rare or non-relevant circumstances, but you are not worth listening to because you do not understand context. This demonstrates a lack of common-sense on your part, nothing else.

Re:Too good to be true

[dougmc]

NiMH and NiCd do have very similar discharge curves for comparable "C" discharge rates. (If you discharge a NiCd at a rate that will discharge it in three hours (to pick a rate), the discharge curve will look very similar to a NiMH being discharged at a rate that will discharge it in three hours. The differences you do see will mostly come from different internal resistances.)

some rare or non-relevant circumstances

What are you talking about? I'm talking about NiMH discharge curves, all of them, not some "rare or non-relevant circumstance".

I'm sorry that you got your information from an incorrect web page, but you did -- NiMH cells start at 1.41 volts, not 1.22 volts, and the discharge curve you explicitly linked to does not represent reality.

This demonstrates a lack of common-sense on your part, nothing else.

Again, I'm sorry that you got some bad information, but you did, and I've shown it to be bad with many different sources.

What would show a "lack of common sense" would be a failure to acknowledge that you repeated some incorrect information, learn from that, correct it, and move on.

not new

[dj245]

This has been around for years. A device from last year uses the same joule thief circuit.

Re:not new

[Anonymous Coward]

So why is this not built in the devices that need it?

Re:not new

[Strangely Familiar]

My thought exactly. This is why one should be extremely skeptical. The article says that none of the circuitry is new, it's only the miniaturization to a sleeve a few millimeters thick that is the trick. So why wouldn't toy manufacturers build this type of thing into their toys to make them last longer? Wouldn't this make people like the toys more? Or at least have fewer gripes? And doesn't every battery powered device need to last longer?

Re:not new

[gl4ss]

So why is this not built in the devices that need it?

but it is.

Re:not new

[ChrisMaple]

Most toys are going to work down to 1 V anyway, at which point the alkaline battery is for all practical purposes exhausted. Although nominally primary cells, alkalines can be recharged if it's done gently. That will provide more life than a booster.

Re:not new

[sjames]

As the baby chick said, cheap cheap cheap!

Re:not new

[camperdave]

So why is this not built in the devices that need it?

Because it cuts into profits.

Re:not new

[Translation Error]

The article itself says it isn't new. What is new is the miniaturization that allows it to go on batteries and have them still fit into existing devices.

Re:not new

[hackertourist]

This is bad advice. I've had an alkaline explode when I attempted recharging it.

Re:not new

[Darinbob]

But can you miniaturize it so that it fits in place in a standard device accepting AA batteries? That's the tricky part that's being done here.

Re:not new

[Darinbob]

Probably cost. Assume that the customer is changing batteries periodically, problem is solved! Consumer electronics is all about cutting costs and corners. My guess is that some devices have this circuit and some don't. This thing is essentially mandatory on some device types; ie, smart water or gas meters and other sorts of remote sensors where changing the battery is a relatively expensive operation. Probably see more of this with the better quality "internet of things" devices that need to be standalone and cant be recharged every night.

Re:not new

[Darinbob]

Depends on the parts inside the devices I think. The example from the article was a bluetooth trackpad. That's a relatively complex device, probably using several chips with specific power requirements. But an older style IR remote control for the TV is going to be easier to deal with large voltage ranges. And face it, the toy companies don't care if you have to change the batteries after a couple of months of playing with their products. Many of those things are dirt cheap and the profit margins of the electronics are so tiny that they can't afford the higher quality.

Don't see this taking off

[viperidaenz]

It's going to be limited to low power device, which generally don't cut out when the battery drops to 1.4V. A lot of products are designed to get the most out of a battery, which is around 0.8V per cell.

High power devices cut out quicker because the internal resistance increases, and when a large amount of current is drawn the voltage drops significantly.

These little devices don't have much power capability if they're to be so small as to fit in existing products along side the batteries. They're also not going to be 100% efficient, so in a well designed product, they will decrease battery life.

Re:Don't see this taking off

[ModernGeek]

This made me wonder why this or similar voltage boosters aren't simply used in the circuitry of the devices that they are powering .. which it sounds like some already are.

Re:Don't see this taking off

[viperidaenz]

Because they cost money.

Re:Don't see this taking off

[dgatwood]

And damage rechargeable batteries by draining them below their safe discharge threshold.

It's just joule thief

[firex726]

It's just joule thief, thing is not all batteries can tolerate being over discharged and may fail catastrophically.

Re:It's just joule thief

[QuasiEvil]

Carbon-zinc and alkaline (MnO2) batteries will go to complete discharge without any danger. You're thinking of various rechargeable chemistries that either suffer loss of capacity from excess discharge (Pb Acid, NiCd, NiMH, etc.) or have the potential to fail horribly (lithium chemistries).

Lithium AAs, while they exist, are fairly rare and not the same chemistry as the rechargables. As far as I know, there's no danger in taking them all the way to dead either.

Re:It's just joule thief

[QuasiEvil]

Leaks and corrosion isn't "fail catastrophically", and typically happens after the battery has been dead for some time and the seals fail. Taking them to zero wasn't the problem - not removing them after they were dead was where the problems started. Many rechargable lithium chemistries, however, will generate oxygen and/or pure metal in bad places if excessively discharged (or charged), which then can translate into burning and toxic gases. Now that's catastrophic.

Re:It's just joule thief

[Khyber]

"Carbon-zinc and alkaline (MnO2) batteries will go to complete discharge without any danger."

Bullshit. Carbon-Zinc batteries use the Zinc can as the cathode. Guess what that means?

As you continue to discharge the battery, the case falls apart because it is eating itself. You get a leak.

Re:It's just joule thief

[sexconker]

Look up the word "catastrophically".
Then look up the word "fail" to find a picture of yourself.

Re:It's just joule thief

[Rhywden]

That's why they have a steel casing around the Zinc, genius.

Re:It's just joule thief

[Khyber]

It still gets corroded through and leaks.

Re:It's just joule thief

[Rhywden]

There's also a plastic hull to contend with. Plus, such a leak is not exactly "fails catastrophically". After all, we're not talking about strong acids or bases here - the most problematic would be the manganese due to its toxicity, it's a heavy metal after all. But as long as you don't eat that stuff, you won't have any problems.

Look at the ingredients - carbon, wet ammonium chloride and zinc chloride as electrolytes / electron conductors, zinc and mangan(IV)-oxide as the electrodes.

There are quite a lot of battery types out there which are much more nasty. This? This is something you can give your pupils to demonstrate how batteries work - it's that harmless.

Re:It's just joule thief

[toddestan]

That's why you replace them when they go dead. Any decent alkaline battery isn't going to leak if you take it down to nothing so long as you don't let it sit for an extended period of time after doing that. Now, cheap Chinese shit batteries you buy at Harbor Freight might be a different story.

Re:It's just joule thief

[toddestan]

They are called lithium batteries because they use lithium as the anode. Lithium is a metal, it's not a synonym for "rechargeable".

Or just use LSD rechargables

[evanh]

Last time I purchased an alkaline cell was one of those button cells, since they don't come in rechargeable versions. Needless to say I avoid devices that use button cells.

Re:Or just use LSD rechargables

[skids]

Most button cells are actually "lithium primary batteries", not considered "alkaline" in common parlance.

Re:Or just use LSD rechargables

[afidel]

Came here to say the same thing, and their target price is WAY too high, I got Amazon LSD AA batteries for $1.50 a piece, you can even get the Eneloop manufactured white amazon basics for under their $2.50 price point.

Sounds suspicious

[diamondmagic]

If this is so great, easy, and cheap to put in (or next to) batteries, why isn't it in electronic devices instead? "Our wireless mouse lasts 8x longer than competitors!"

This also sounds like snake oil from a salesman who doesn't know about the law of conservation of energy:

“The time it takes for the battery voltage to drop by 0.1V is longer at lower voltages versus at higher voltages. That means that if a constant current was drawn from the battery, it would take the battery a lot longer to discharge from 1.2V to 1.1V than it would from 1.5V to 1.4V. This means that the extent to which the battery life is increased could be even higher.”

If the battery is serving a lower voltage, that means it must put out more current. So, they've either broken physics, or just no.

Re:Sounds suspicious

[Khyber]

The boost converter will run as low as 0.6v. That IS an improvement, since most devices DO power down at 1.0v. But I also call hogwash on the "no extra risk of leakage". Alkaline cells use an inner layer of the case as the cathode. This inner case is invariable damaged by discharge. The deeper the discharge, the more severe the damage. Most reasonably modern C/Zn and AM cells have a second can outside of the first one to reduce the risk of leaks. But the battery may still fail and leak, and the fact that you have a weak battery in your device for longer RAISES your risk of a leak.

Plus, more hogwash. The "voltage drop slows at lower voltage levels". Alkaline batteries really do have a fairly linear discharge curve for SoC. The dubious claim that it slows is assuming a continuous resistive load, which by Ohm's law says that power will drop 4x for each 2x drop in voltage.

Not to say these boosters aren't useless. If your device shuts down at 1.3v (not unreasonable for older generation digital devices), you can use that battery for a lot longer. And where these things really come into their own is on rechargeables that OCV at a lower voltage that may fail to drive certain devices.
There IS a caveat though. A very, serious, caveat.

You lose ALL SoC INFORMATION IN THE BATTERY.

When you connect a booster, you forfeit all advance warning that your battery is low. You're at 1.5v until you aren't and you're high and dry.

And of course battery companies are going to be thinking of chemistry. Because implanting a $10 booster into every $1 AA alkaline battery is going to make these cells prohibitively expensive.

It's definitely a cool device, but it's not worth the hype this author is giving it.

Critical warning. This is an active circuit you're placing on your battery. Alkalines have always shined in very low current applications. Attaching an active converter circuit will put a continuous (though light) load on the battery, slashing its shelf- and very-light-duty life.

Over the span of 60 hours in a Game Boy, it's not much. But over the span of a year or two in a desk clock, it becomes significant.

Potentially significant enough to fully offset and even overcome the "unlocked" power now available to you by using it at the lower voltage.

Depending on what you're doing with your battery, you could see -50% through +300% lifespan. Degradations are for microamp-scale super long life devices, where the load of running the Batteriser forms a significant fraction of the running power. Biggest boosts are for devices that shut down at abnormally high voltages.

Re:Sounds suspicious

[serviscope_minor]

The boost converter will run as low as 0.6v. That IS an improvement, since most devices DO power down at 1.0v.

Funnily enough I actually built something like this for a school project a little under 20 years ago. Naturally the batteries were external and the convertor box was large, but that's not the point. The point is that the battery discharge curves are very far from linear.Just google "battery discharge curve". While they vary, the essential characteristics are the same:

http://robotics.stackexchange....

The voltage quickly drops down to the nominal voltage from the fresh voltage [*]. It then very slowly drops until the battery is exhausted at which point the drop is catastrophic. At the corner, the chemical energy is nearly gone and the internal resistance goes way up. So, probably 95% of the battery energy has gone by the time the cell hits 1V. While you can scavenge the remainder between 1 and 0.6, there's little energy there and the voltage will drop very very fast so it won't last long.

[*]And here's where the deception comes in. They claim that people discard batteries at 1.3V, which is not true. That's the point where the batteries finish the initial rapid drop off and start the long, slow discharge curve. No one throws them out then since no equipment minds---the equipment makers know to expect voltages down to about 1V and build accordingly. NB if they didn't, rechargable batteries with a nominal voltage of 1.2V would never work.

So, their claim is true if people discard alkaline batteries at 1.3V. However people don't.

Re:Sounds suspicious

[sjames]

There are a very few devices that will cut out at 1.3 (and so, the instructions insist on alkaline batteries). They must have searched long and hard to find one of those oddities to "legitimize" their claims.

What I imagine will happen from this...

[mark-t]

Since this requires an external sleeve to be mounted on the battery... I expect this will more than likely cause the battery to not fit properly in many types of devices' housing. Some people may try and force the battery to fit, and might end up breaking their devices, often without even necessarily using very much force (since the only force batteries generally require to insert in most consumer devices is against the spring tension of any battery contacts).

Re:What I imagine will happen from this...

[PitaBred]

The whole point is kinda that it DOES fit. It wouldn't even be a product if it didn't fit, as the circuits and everything else is fairly well known.

Not very useful

[ZackSchil]

There aren't many devices that are both low power and require a steady 1.5V operating voltage. Most will tolerate 0.8-1.2V as their low end. In a high drain device, the number of watts left in the cell when the voltage drops below that low end is minuscule, so this sleeve will only buy you a few more minutes of use. In a low drain device, it can give you a significant amount of time but most low-drain devices that would benefit already have a similar circuit built-in. Logitech's wireless mice and keyboards that use alkalines and last months, for example, have this voltage boosting circuitry already, and tuned to the minimum voltage the mouse requires to reduce conversion loss.

Re:Not very useful

[Khyber]

"There aren't many devices that are both low power and require a steady 1.5V operating voltage."

Cameras are quite voltage sensitive. Example, two cameras I own came with 1.2V cells. Two for a total of 2.4V. Recording video in bright lighting conditions is fine. The second you drop past a certain light level, the audio capturing/encoding gets beyond fucked, and everything sounds like a chipmunk, even sped up. This does not happen with 1.5V alkaline batteries inserted.

Re:Not very useful

[thegarbz]

What you're saying is you have a camera with a very poorly designed power system. Case in point a high discharge device being designed to be used with a non-rechargable chemistry. If a camera can't handle 1.2V cells and runs from AAs then the designer should have their ass kicked.

Re:Not very useful

[ihtoit]

Kodak Easyshare C633.

Great on fresh alkalines, take a dozen flash shots, it's fucked. Or is it?

Drop the batteries into an LED flashlight like a "Lenser" which are loaded with Cree electronics, and they'll last another three years.

Source: I have a drawer full of cameras and flashlights are the cornerstone of any discerning hunter's day pack.

Re:Not very useful

[thegarbz]

Oh I believe it. I came across it on an older Olympus model too. That's no excuse for crap design though.

Re:Not very useful

[Khyber]

Shit you even got almost the EXACT models of camera down. Easyshare C643 and C743. My Z981 doesn't have this problem.

Still waiting for 1.6V Ni-ZN batteries to get their whiskering problem fixed.

Already within power circuit or useless

[La Gris]

When a device power circuit already integrate a voltage regulator, this is yet another battery scam.
If not, it is either a cheap or old piece of electronic.

This battery extender _is_ yet another battery scam.

Next expand your car mileage by adding a water sprayer, magic canister?

This is not news for nerds.

_This_ is scamvertisement.

Re:Already within power circuit or useless

[Megane]

If they can make it work, I'd buy some. But I will not indiekickfund it. The magic is not the boost converter, it's making it that small and thin. I don't feel confident enough about that to place a bet on it until it's already worked for other people.

1.5V alkaline vs 1.2v NiMH

[lindseyp]

"A completely new alkaline battery is rated to generate 1.5 volts, but once its output drops below 1.35 or even 1.4 volts, it effectively becomes useless to many devices. "

And yet I can't recall any device that didn't work happily with the 1.2v supplied by a rechargeable NiMH.

Re:1.5V alkaline vs 1.2v NiMH

[gweihir]

And that is exactly the problem with this "invention": And sanely designed device these days assumes batteries may be NiMH. These start at around 1.22V when full and are empty at somewhere around 1.10V. That means this "magic" "invention" will boost battery life by something like 70% or less in such a device. And using NiMH in the first place is a better choice anyways in most applications.

Re:1.5V alkaline vs 1.2v NiMH

[djbckr]

And yet I can't recall any device that didn't work happily with the 1.2v supplied by a rechargeable NiMH.

To add to this good statement: Alkaline batteries have high internal resistance, so when they are highly loaded, their voltage drops dramatically (and therefore become useless to the device they are powering). NiMH have low internal resistance and can delivery drastically more amperage before their voltage drops. Many devices completely work with 1.2v just fine, but alkaline batteries drop below that too easily.

Re:1.5V alkaline vs 1.2v NiMH

[QuasiEvil]

Yeah, the 1.35 or 1.4 number is total bull$#@!. Almost everything these days will run on the 1.1-1.2 of NiMH, as you point out. Even at that point, the remaining energy in a common alkaline (manganese dioxide) AA cell is nowhere near 80%. Alkaline goes "over the cliff" - the sharp point at the end of the discharge curve where there's no energy left and the voltage plummets - at about 0.8-0.9V. Even at 1.1V, there's only about 10% of the energy capacity left for a typical alkaline.

Look up "alkaline discharge curve" pretty much anywhere. Typically these will plot output voltage on the Y axis and amp-hours on the X axis. The energy remaining is the area under the curve to the right of where you're looking (because energy is measured in watt-hours, and voltage * amp-hours remaining is watt-hours). As you extract more energy (move right on the X), your voltage drops. When you hit a certain point... boom! straight to the floor.

Most battery powered devices these days either have a switching regulator that deals with this issue, or they use a low quiescent current, low dropout regulator and a big enough battery stack that can keep the supply rail where it needs to be until the batteries hit their dead point. While not strictly a scam, it won't do much good in most modern devices (and will actually decrease performance in well-designed ones, as I'm sure the switcher in these has a non-zero quiescent current, and an efficiency below 100%).

Re:1.5V alkaline vs 1.2v NiMH

[hawguy]

"A completely new alkaline battery is rated to generate 1.5 volts, but once its output drops below 1.35 or even 1.4 volts, it effectively becomes useless to many devices. "

And yet I can't recall any device that didn't work happily with the 1.2v supplied by a rechargeable NiMH.

The remote for my old Sony TV refused to work with NiMH's, but since the remote lasted for a couple years of regular use with a pair of Alkalines, this $10 battery booster wouldn't really be worth it.

Re:1.5V alkaline vs 1.2v NiMH

[viperidaenz]

Great, add this boost converter to the battery, and watch the quiescent current flatten the battery faster than the clock you're trying to power!

Re:1.5V alkaline vs 1.2v NiMH

[fnj]

All the devices I happen to have that use AAs will work just fine down to at least 0.9 v. Some of them work to 0.7 v.

Re:1.5V alkaline vs 1.2v NiMH

[YoungHack]

This is no joke. I made a clock once with a circuit like this and the quiescent current did exactly that. I removed the booster, and just ran the clock on two batteries and it runs a long time now.

Re:1.5V alkaline vs 1.2v NiMH

[Miamicanes]

The catch is, not all devices (especially devices more than a few years old) ARE "sanely designed". I remember quite well that the original Palm III had fairly demanding battery requirements... it was good for about a month with Duracell or Energizer alkalines, but only lasted 2-3 weeks with store-brand alkaline cells, and only lasted a few DAYS with NiMH cells. Ditto for my piece-of-shit Minolta d'Image DSLR, which was good for about 10 photos on brand new alkaline batteries before shutdown.

That said, the marketers behind this aren't being entirely honest... they're presenting the best-possible and most extreme edge case as the universal norm. It will make a HUGE difference for some (badly-designed/cost-cut) devices, and make no positive difference for well-designed devices. Regardless, it'll be useful, because shit devices vastly outnumber well-designed ones.

Re:1.5V alkaline vs 1.2v NiMH

[sexconker]

I had walkie talkies (the biiiiiiiig ones) that used this scheme.

Re:1.5V alkaline vs 1.2v NiMH

[ihtoit]

older digital cameras.

source: I have many, and they all suffer the same problem: they don't work on NiMH chemistry. ANY of them.

Re:1.5V alkaline vs 1.2v NiMH

[ihtoit]

yep, I had two that had that. One was a Harvard Multi (UK, CEPT & sidebands), the other a Radio Shack 80-channel (UK & CEPT). Both ran on 12V (8xMnO or 10xNiCd - 8xNiCd wouldn't work). I was so happy when I got my Yaesu VX-5 apart from the fact that it doesn't cover MPT-27/81 or CEPT, 49MHz unlicensed or anything above 999.90MHz. Guess I'm stuck using terrestrial bands that everybody else uses. :(

Re:1.5V alkaline vs 1.2v NiMH

[wbo]

The old PalmOS devices had options to select which battery chemistry were in use. If I remember correctly, support for recharable batteries such as NiMH cells was added somewhere around PalmOS 3 or perhaps 3.3. A reference page indicates that Alkaline, NiCad, Rechargeable Alkaline, and NiMH were supported.

If you didn't select the correct chemistry it could report the batteries as being dead or almost dead when they still had lots of life left.

I had a Palm IIIx that I used for many years and I ran it almost exclusively off of NiMH batteries with no problems. If I remember correctly I had the charge the batteries around every 2 weeks or so.

Re:1.5V alkaline vs 1.2v NiMH

[fgouget]

Try a Canon PowerShot A1100 IS. Dates back to 2009, still works just fine with NiMH batteries.

Re:1.5V alkaline vs 1.2v NiMH

[istartedi]

You can go back even further than that with the PowerShot line. I have one from 2007 that works fine with NiMH.

Re:1.5V alkaline vs 1.2v NiMH

[gweihir]

If it worked at all with NiMH at all, then you get at most 100% battery life extension for alkaline from this device. I would say that 100% in comparison to the claimed 500-800% qualifies as direct and drastic lie, not as "not entirely truthful".

Re:1.5V alkaline vs 1.2v NiMH

[ihtoit]

Kodak Easyshare C633, c.2006. Mn-O: fine. Ni-MH: no chance. Zn-C: nope. Ni-Cd: Hell no.

Re:1.5V alkaline vs 1.2v NiMH

[gzuckier]

Yeah, the 1.35 or 1.4 number is total bull$#@!. Almost everything these days will run on the 1.1-1.2 of NiMH, as you point out. Even at that point, the remaining energy in a common alkaline (manganese dioxide) AA cell is nowhere near 80%. Alkaline goes "over the cliff" - the sharp point at the end of the discharge curve where there's no energy left and the voltage plummets - at about 0.8-0.9V. Even at 1.1V, there's only about 10% of the energy capacity left for a typical alkaline.

Look up "alkaline discharge curve" pretty much anywhere. Typically these will plot output voltage on the Y axis and amp-hours on the X axis. The energy remaining is the area under the curve to the right of where you're looking (because energy is measured in watt-hours, and voltage * amp-hours remaining is watt-hours). As you extract more energy (move right on the X), your voltage drops. When you hit a certain point... boom! straight to the floor.

Most battery powered devices these days either have a switching regulator that deals with this issue, or they use a low quiescent current, low dropout regulator and a big enough battery stack that can keep the supply rail where it needs to be until the batteries hit their dead point. While not strictly a scam, it won't do much good in most modern devices (and will actually decrease performance in well-designed ones, as I'm sure the switcher in these has a non-zero quiescent current, and an efficiency below 100%).

useful for incandescent bulb flashlights.

Re:1.5V alkaline vs 1.2v NiMH

[gzuckier]

get 3 volts for an led out of a single 1.X v cell

I'm not impressed.

[fuzzyfuzzyfungus]

Ok, DC-DC converters do have a legitimate place in battery powered systems. You want a blue or white LED in your flashlight without resorting to an expensive cell chemistry or 3ish alkalines in series? Well, DC-DC converter it is. You(for some reason) have an antique filament-bulb flashlight and you don't want it to spend the last chunk of its life putting out relatively useless IR because the filament temperature is too low for visible light? A DC-DC converter will fully flatten the batteries faster(because of its own losses, and because current draw has to increase as voltage droops in order to maintain the same power output); but at least the entire lifespan will be spent putting out usable light.

However, there's a problem here: Most even vaguely well designed widgets already tolerate some amount of voltage variation. Especially because NiCd and NiMH rechargeables are only good for ~1.2v(maybe 1.3-1.4 hot off the charger, for a few moments), alkalines for ~1.5; but with well known droop as they are exhausted or if discharge current is too high; and lithium primary cells in AAA or AA packages are up around 1.7, with less droop; you simply can't build a consumer widget that is too picky about battery voltage. If you do, you'll be flooded with unhappy and confused customers and probably lots of expensive returns.

This seems to constrain the useful market for this product to a very narrow, rather weird, niche: Anything that already tolerates voltage droop well will see very limited benefit. Anything with very low power draw will also see very limited benefit, because even badly depleted batteries slump as discharge current increases. Devices with very high power draw might see a benefit; because they will drive the battery to slump most quickly(and, according to the discharge curves for most alkalines, very high currents will cause substantial slump well before the capacity is exhausted); but the DC-DC converter will need even higher discharge current in order to keep power output constant as voltage drops, which will exacerbate the voltage slump, and likely hit the wall where the effective internal resistance of the battery is high enough that it simply won't deliver any more current.

So what actually gains? Devices that are maldesigned enough to brown out with even modest voltage droop; but also sufficiently low drain that the draw of the converter will remain within the battery's 'best-case' discharge cycle; but not so low drain that the (modest; but nonzero) losses in the DC-DC converter increase the overall drain by a substantial amount.

Anyone have a device or devices in mind?

Bull. Shit.

[jtownatpunk.net]

If this "technology" actually worked and the only innovation here is the miniaturization, it would have been built into the battery compartments of devices already. It sounds almost as legit as magnetic fuel optimizers.

Not a linear relation

[ortholattice]

Alkaline battery voltage doesn't fall linearly with lifetime, but undergoes a rapid drop near the end of life: http://www.powerstream.com/z/A... In this curve, the battery has only 10-20% of its life left at 1.1v, and I've never owned any device that did not work down to at least that voltage and usually less. Whatever device in the example that stops working at 1.35v is very poorly designed and not something you run across often.

Impractical

[jgotts]

AA batteries are $1 for a four pack at the dollar store. That's 25 cents per battery. Admittedly, these batteries are low end. If you use one of their coupons, Harbor Freight sells their private label AA batteries for about 25 cents when you buy 24.

Let's say that I'm using a 4 AA cell device, my old camping lantern. It has one dollar worth of batteries and $10 worth of these devices. The lantern itself isn't even worth $10. Seems like an awful lot to spend to me, because the $10 investment becomes a permanent part of the lantern. You don't swap it around. For each device you need 2, 4, 6, or 8 of these things.

More logical than buying this product would be using rechargeable batteries, but for me even that is a tough sell because I recycle alkaline batteries.

May be of some use

[Gim Tom]

I have a number of wireless devices ( remote thermometers, rain gauges, etc ) that use AA and AAA cells and I have tracked the failure voltage of most of them for several years. I fresh cell will be a bit over 1.5 volts and good design SHOULD permit operation down to about 1 volt per cell. However, virtually all of the devices I have quit working when the cell voltage gets below about 1.34 volts. The devices use between 2 and 4 cells each, and I have to change batteries in most of them between one and two times per year. I AM an engineer and understand that "there ain't no such thing as a free lunch" but most of the devices are low average current drain with intermittent higher current peaks (a sensor that transmits a new reading every couple of minutes). A device like this, with an appropriate capacitor for peak current (which most of the devices already have internally), would cut down the number of batteries I use per year significantly. For the price mentioned in the article I will buy a few sets of these as soon as they hit the market.

Re:May be of some use

[Ramze]

Why? That just doesn't strike me as being very cost effective.

If the plan is to sell a pack of 4 sleeves for $10 to go with a pack of 4 alkaline batteries ($3 for Rayovac, $6 for Duracell around here), you could instead buy 4 Panasonic eneloop Ni-MH AA batteries for $13. You would, admittedly, have to pay for a charger and charge them beforehand, but you'd save lots of money over the life of the rechargeables. The Panasonic chargers go for between $7 and $14, but I highly recommend a La Crosse Technology brand recharger with LED displays and more sophisticated modes and options. -- they run around $35 to $40 on Amazon.

I've had nothing but eneloops for about 7 years now - they run in my electric toothbrush, my remotes, mouse and keyboard, etc. They're rated for over 2,000 charges each and I'm nowhere near that limit. As for voltage, they're designed to have a lower internal discharge rate than most rechargeables and a much higher and more stable voltage than most alkalines -- typically staying above 1.1 volts 'til they "die" and require a recharge. This means they last longer both when the device is not in use (not draining while resting), and last longer while in use because the voltage doesn't drop until it's drained.

I only had a problem with one device -- its tiny form-factor wouldn't let me squeeze the eneloop AAs inside as they're slightly thicker than a regular AA.

I've tried many rechargeables for decades and many were failures - largely because they failed to hold a charge or recharge well at all. Eneloops changed the game for me. They were originally made for cameras that required a higher stable voltage and used to be quite expensive, but the prices have dropped drastically.

Now, I haven't researched others as I haven't had to buy a AA or AAA in 7 years, but I'm sure there are others out there that perform as well or better by now.

Not the most scientific review, but here's one example of testing them against alkalines and other rechargeables:
http://antonovich.me/2014/6/5/...

Notice specifically the yellow voltage line for the eneloop AA rechargeables. After about 3 hours, all batteries dropped to 1.2 volts, but the eneloop stayed there longer and continued to stay between 1.1 and 1.2 volts for about 5 more hours while almost all the rest dropped off. Looks like the Varta ready2use NiMH beat them on overall life, but not by much.

http://antonovich.me/media/upl...

Re:May be of some use

[Ramze]

D'oh! My bad.

Darned my eyes... I saw the 1.5 V and the 1V, but completely missed the 1.34V in the GP post. Probably because I did see it, but found it too incredulous to process. I may have presumed it to be a typo. Most any use of say, 100 mA would drain a Duracell battery below that voltage within 3-4 hrs of use. But, if this device pulls 500 mA, it'd only take about 10 minutes to go below that mark.

http://lygte-info.dk/review/ba...

I guess the real question is - what devices require 2 to 4 AA batteries and are designed so poorly that they won't work with typical AA battery voltages? Most often, a device uses more cells specifically to boost the voltage. Rarely do you find cells in parallel. So, if these devices kick off at 1.34 volts, it's because they won't run with less than 2.68V or 5.36V and they fail to have good internal voltage regulators. You may be better off buying better devices? None of mine show a battery as dead until it's at least below 0.8V and they range from electric toothbrushes to TV remotes, Wii Controllers, mice, keyboards, clocks, and LED lamps. I'm curious as I've never come across this problem.

On the surface, I'd say that you're correct that a 1.5V joule thief battery would suffice if this is indeed an issue; but, changing AA batteries once or twice a year (as the GP says) is still likely to be the case - the trade-off for stabilizing the voltage is that the batteries will drain amps to maintain the 1.5V - even when it doesn't have to. Say the device could run on 1.4V, but the unregulated voltage booster will bump it to 1.5V anyway.

I also wonder what the internal drain of the batteries are and whether these devices are truly off when not in use or if there is a "vampire drain" that exists even when off. If there is a drain, will the battery booster try to deliver 1.5V even when the device is "off?" Wouldn't that drain it further as well?

In any case, the new device seems to work with both alkaline and NIMH rechargeable batteries equally -- and the eneloops drop off voltage the same or better than alkalines even in the 1.5 to 1.3 range as well, so going with rechargeables is still a good idea.

You can even get cases for the AA ones to make them fit into C and D cell devices, though I haven't tried it myself.

Re:May be of some use

[fgouget]

However, virtually all of the devices I have quit working when the cell voltage gets below about 1.34 volts.

This is strange. All the devices I have work just fine with NiMH batteries and these are 1.2V. (LED flashlights, basic remote controls, Harmony-with-screen remote control, 2 wireless keyboards, 1 wireless mouse, 3 alarm clocks, SLR camera flash, bathroom and kitchen scales, cd player, 90's walkman, cordless phones)

Re:May be of some use

[Gim Tom]

Both your initial reply and addendum are good points. I do have a lot of eneloop batteries and charger and use them in my cameras and other places where ever they seem to work well. I have not tried them in these weather sensors (which are very old and undoubtedly poorly engineered) this is probably because when I take two 1.2 volt eneloop cells I get only 2.4 volts and these devices fail to function when the alkaline cells drop below about 1.34 volts per cell which is 2.68 volts and this is higher than the initial full voltage of two eneloop cells. Next time I have to change batteries I WILL probably try the eneloop's just to see if they work at all.

The sensors have average current drain in the microamp range except for a brief burst of only a few milliseconds when they transmit a reading. Then they draw several milliamps for that period.

Re:May be of some use

[Gim Tom]

I know. A well designed circuit for battery power SHOULD work down to about 1.0 volts per cell. These are very old and very cheap sensors that are imports and do not come close to that threshold.

For the sensors I am using the average current drain is in the microamp range except when transmitting a reading, which takes only a few milliseconds, and are several minutes apart. The transmit current is in the low milliamp range, but so brief that the average current drain is less than one milliamp.

I do have and use eneloop rechargeable batteries in many other devices, but have not tried them in these since the 1.2 volts per cell is below the 1.34 volts per cell where the alkaline cells fail. However, I plan to try some the next time I have to change the batteries. Perhaps combining the voltage booster in the original post with the rechargeable cells would be the best of both worlds.

By the way, the 90's walkman was a far better case of engineering design than these sensors!

Re:May be of some use

[chihowa]

Any piece of modern day electronics of any value is already using an internal voltage booster if low current and long battery life is expected.

"Of any value" is the catch here. Eliminating the boost circuit makes the device cheaper to manufacture and offloads that cost to the operating cost for the user (which means higher profits for the manufacturer). The devices that he's talking about (remote thermometers, rain gauges, etc) probably tie him to a single manufacturer, so there's no competition anyway.

Modern day engineering of consumer devices is almost completely rooted in "value engineering". For an expected level of function, everything that isn't absolutely necessary is cut from the design (from quality of components to niceties like efficient use of batteries). The target for expected level of function is a distribution just to the outside of the warranty period.

Re:May be of some use

[toddestan]

Exactly. A battery that's near the end of its useful life but not completely dead can register a decent voltage measured with a voltmeter, but a battery tester which puts a load on the battery (usually just a resistor in parallel) then measures the voltage will show the battery as nearly exhausted cell that it truly is. A lot of sensors like that I have seen recommend lithium batteries (the non-rechargeable type) as they will perform better for the short, high current draw situations when the sensor takes a reading. And I've generally found that is true.

Re:May be of some use

[Ramze]

Ahhh... That makes sense. For the life of me, I couldn't imagine a use case where this would happen. Just shows my lack of imagination ;-) Thank you for the reply. This explains perfectly how you get a relatively long battery life with a higher than usual required voltage. -- low power except for transmission spikes, older design (likely pre-rechargeable era).

The newer Slashdot post follows up on the debunking of the overblown claims of the joule thief:
  http://www.eevblog.com/2015/06...

It hits all my points far better than I noted -- the most important being that most devices today are designed with the rechargeables in mind and/or have their own internal regulator making this thing moot... and also point out the flaws in logic of how much this would actually extend the use of the batteries even for cases like yours where it really might help.

I hope you get the chance to try these out to see whether they can help you. Depending on your setup, it could be a cheaper alternative to switching out that equipment. Best of luck to you.

As an aside: I have cheap outdoor thermometers that run off of AAs and transmit to a unit inside (one for the back porch and another for the greenhouse) They're cheap recently purchased AcuRite devices; but my uncle has a sophisticated system for his farm. I was recently looking into arduino and raspberry pi alternatives - and there's some really nice advancements in that area that may become cheap alternatives in the near future.

Re:Lots of negative nancies in here

[msobkow]

Technology may get better, but the rules of electrical circuits, physics, and so on rarely change enough to make a difference on a planetary scale. Unless there has been some earth-shattering change in the way electricity works, it's a scam.

Re:Lots of negative nancies in here

[gl4ss]

chances of them finding out some new chemical properties universal to all batteries and announcing them this way: 0.000000001%

chances of the tech being already existing and integrated into most devices that would benefit from it: 99.99999%

they're more like a posse of people trying to sell you a ram packer that will make your 640k function like 5120k

Digital cameras

[Radical Moderate]

I've had 3 or 4, different brands, that after a year or so would only work with brand new batteries for a few shots and then quit, and forget rechargeables. Now that phone cameras have become good enough, I haven't owned an actual camera for some time, maybe they've improved.

Re:Digital cameras

[fgouget]

Did you have a Canon among them? At least their Canon PowerShot A1100 IS from 2009 still works just fine with NiMH batteries.

Difference between lifetime and energy recovery

[goombah99]

The voltage curve for most Alkaline batteries hits 1.3 volts after about 20 to 30% of it's usefully extracable energy. then the curve flattens out dropping the next 0.3 volts to 1 volt after about 70 to 80% of the energy after which is drops like a rock.

So if you could reclaim that 80% energy that might seem like 4x more or a total of 5x energy recovery. But the boost to 1.5v takes the energy out faster so in terms of time rather than energy recovery the lifetime is not increased so much.

let's make some guesses and see where that gets us. Assume that there is a 0.2 volt diode drop somewhere in the system--- this seems pretty likely for any active circuit. So that means it's effectively boosting to 1.7 volts then the diode takes a cut. I can't do the integral in my brain so lets assume that the mean voltage it is boosting from is 1.1volts. So going from 1.1v to 1.7 volts means it is extracting about 33% more current than is actually in use. Thus it seems like this thing is going to suck down the battery pretty fast.

So yeah it recovers all the energy which might be 5x a normal 1.3 volts cut out. But it wont last 5x longer cause it takes a big cut.

Re:Difference between lifetime and energy recovery

[sexconker]

it's means it is.

Not necessarily. You fucking poser grammar Nazis don't even know the rules, yet you try to enforce them. Pathetic.
It's been fun owning your ass, though.

Re:Difference between lifetime and energy recovery

[sexconker]

That's a question you should ask yourself, Megatron.

Re:Lots of negative nancies in here

[Nutria]

Too bad that "640K ought to be enough for anyone" was an urban legend.

Hey, c'mon everybody!

[fustakrakich]

It's a battery for your battery.. Where's all the yo dawg shit?

Re:Hey, c'mon everybody!

[gzuckier]

It's a battery for your battery.. Where's all the yo dawg shit?

Hey, a hybrid battery' with a tiny gas tank and motor and generator....

Single Battery LED flashlights

[xs400]

I specifically look for single cell LED flashlights that have the voltage boosting circuit built in. Most el-cheapo double / triple cell LED flashlights die out much faster because they rely on the cells in series to supply the required voltage. This product will be a success IMHO.

Fit problems

[hackertourist]

So this device fits around an alkaline battery. I've got a Wensn decibel meter that has a battery compartment big enough for alkaline AAs, but too small for any of my rechargeable AAs. The rechargeables have a slightly bigger diameter (the difference is 0.2-0.3 mm).
So there's a chance alkaline batteries using this device won't fit.

Would this work for NiMH Rechargeable?

[MightyDrunken]

I now use NiMH AA batteries for almost everything, with the low discharge varieties like Eneloop/Panasonic I see no reason to use alkaline batteries which are, in the long term, more expensive and less environmentally friendly. However every so often I find a device which does not like NiMH batteries, presumable because they expect a voltage higher than 1.2V. If so this device could boost the voltage to 1.5V meaning I could use rechargeable batteries for everything.

Rechargeables are still better!

[Anonymous Coward]

For the price you can just by a 4 pack of NiZn Rechargable Batteries with 1.6V operation voltage . Id rather give some extra money to have sleeves that protect my rechargeables from getting discharged to far down. Not this joule thief sillyness because batteries are a waste in it self.
The whole story sounds like stealth marketing anyway.

Sort of old idea

[Reisrdok]

Have been doing similar devices to friends for many years.. For eg. device with three AA batteries, one battery is replaced with small 4.5V switcher power supply (with small ground wire to first battery). Keeps constant 4.5V output until batteries are very dead. Was specially useful with old flashlights, you could increase voltage to bulb limits and turn old Maglite to light cannon :D Well okay, maybe not that impressive, but better still..

Re:Lots of negative nancies in here

[ihtoit]

"There is no reason for any individual to have a computer in his home."
  - Digital founder Ken Olsen, 1977, and yes he did in fact say this at the World Future society event in Boston during a talk.

There is some use

[TomGreenhaw]

While the claims are obviously exaggerated, I'll use them for some things.

How about a flashlight where the bulbs don't get slowly dimmer. Its basically adding voltage regulation and boost to simple devices that don't have that.

other batteries

[kqc7011]

I hope that eventually this will work with 18650's as bright flashlights are battery hogs. Oh, and my mouse needs freshened Eneloop's about once a week and if this can extend the time between changes to twice that I will gladly buy a set.

Re:Info needed

[fraxinus-tree]

You cannot damage a single NiMH (or NiCd, for that matter) cell by simply draining it down to 0v. Well, you will have to use a "stupid" charger to wake it up afterwards, but the cell will be otherwise ok. Then again, you rarely use a single cell. Generally, you connect 2-4 of them in series. When you discharge them, they will hit the 0v in slightly different moments. The first one that gets to 0 will continue getting a discharge current and will actually go below zero (reverse polarity) with all the nasty things the reverse polarity does (electrolyte depletion, gas build-up and venting).

Eneloop

[nhat11]

Best rechargable batteries that I ever got, takes months to discharge and last for years.

Cost of Batteriser

[jan_jes]

The Batteriser will come in AA, AAA, C and D-cell varieties and sell for less than $10 for a pack of four. We can buy it in Amazon by the end of September.

Re:Solution in search of a problem

[EmagGeek]

Few battery powered devices don't already have a boost converter built in. Most wireless mice, for example, have two AA batteries in parallel and boost the voltage to whatever it needs, be it 3.3 or 1.8 or whatever.

A silly idea

[Dribbitz]

Besides the mentioned error in estimated reserve energy capacity:

Back in the days of carbon-zinc batteries, you could safely run them down to "near-dead" (~0.6v) and they would keep their physical integrity, for up to a few months perhaps, before the zinc outer casing ate through and exposed the corrosive electrolyte paste to the insides of your hapless electronic device.

If you do that with an alkaline battery, they tend to start leaking a corrosive liquid much more quickly, in days to weeks. And their liquid leakage gets everywhere and is more damaging.

This "Batterizer" idea isn't being promoted by someone who understands battery physics.

Re:Lots of negative nancies in here

[Nutria]

Gotta love context-free quotes!!

http://www.snopes.com/quotes/k...

[That interpretation of my comment] is, of course, ridiculous because the business we were in was making PCs, and almost from the start I had them at home and my wife played Scrabble with time-sharing machines, and my sixth-grade son was networking the MIT computers and the DEC computers together, hopefully without doing mischief, using the computers I had at home. Home computers were a natural continuum of the "personal computers" that people had at work, in the laboratory, in the military.

Example device

[jacksdl]

I am using a Microsoft Wireless Notebook Presenter Mouse 8000 that I constantly change alkaline batteries in. NiMH won't work. So this must be a example of a device that insists on 1.3V or more....

Primary alkaline batteries can be recharged

[edtice1559]

It's messy (sometimes you get leaks) and the recharged versions don't last as long, but you can extend the life this way. I have no idea what the market for this product is, though. For my devices that go through power quickly (I have a four year old, and just about everything he owns requires 3-4 AA batteries) I use NiMH rechargable. For things that only need a new set once a year or so (remote controls) I recharge primary alkalines. I realize that there are people out there who can't be bothered, money is no object, and they don't care about what they put into landfills. But they aren't going to buy this product either. I have no idea who would be the target market. And, as others have said, this circuitry belongs in the device, not the battery. And most devices have it. I don't have a single thing that won't work off of the 1.2V supplied by NiMH.

This would be great for improving NiMh batteries

[juancn]

NiMh batteries are usually 1.2 volts. If this were integrated into the battery so it provides a discharge profile similar to Alkaline, rechargeable batteries suddenly become practical for many devices that don't know how to deal with them.

I suppose industrial espionage isn't interesting..

[guardian-ct]

First three paragraphs of the story tell of thieves breaking in to the office and stealing information about how this thing works. Is this not worth putting into the summary?

Re:Info needed

[operagost]

The proper usage cycle for NiCd actually REQUIRES that you drain them completely to avoid memory effects.

Re:Info needed

[gTsiros]

the memory effect is very very unlikely (practically impossible) to happen in commercial hardware, even if you try to demonstrate it.

it can only present itself when the battery is discharged and recharged under the exact same cycle for thousands of cycles

it's been observed in satellites but there is no scenario where this will occur in commercial usage. Only under laboratory conditions.

Re:Info needed

[gTsiros]

all secondary cells nicd/nimh/liion/etc have a characteristic voltage curve. They start at well above their nominal voltage and can drop well below

Applied to LED Flashlights & Headlamps for Hik

[Irate Engineer]

A problem that has been the bane of evening hikers is that LED headlamps suddenly quit when the voltage drops below a certain level, even though the battery may still have a considerable charge remaining.

We miss the old days of incandescent bulbs where you at least had some warning of a flat battery as the light faded in a slow, predictable manner, which gave you time (and light) to dig out fresh batteries or otherwise manage the situation. LED lamps tend to just die without much warning, and Murphy's Law requires that the lamp will fail when you are doing something dangerous that requires special care with your footing.

If this technology is available at the consumer level for headlamps and such, we'd love to hear about it.

Too bad i doesn't help stop electrolyte leaks

[hwstar]

Overdischarging alkaline batteries may cause them to leak, ruining the gadget containing the batteries. The cheaper no name budget cells are notorious for doing this.

Re:Info needed

[dgatwood]

You cannot damage a single NiMH (or NiCd, for that matter) cell by simply draining it down to 0v. Well, you will have to use a "stupid" charger to wake it up afterwards, but the cell will be otherwise ok.

If the charger is too dumb (lacking thermal sensors), I'd be concerned with overheating the cells and starting a fire (though not nearly as spectacularly as with lithium ion chemistry). You do, of course, have to use a charger that won't cowardly refuse to charge a cell that is fully depleted.

Re:Info needed

[dgatwood]

In practice, you're much, much more likely to have cells become nearly dead shorted because of dendritic growth caused by cell reversal in a pack. Such dendrites dramatically reduce the pack's overall capacity and increase its self-discharge rate. This is why discharging packs to nothing is a very bad idea unless you either do it one cell at a time or do it extremely slowly.

Debunking video

[janoc]

Dave from EEVBLOG is on the case already: https://www.youtube.com/watch?...

If you don't know the fellow, he is a professional EE with a wee bit of background and qualifications in these things.

I asked them about NiMH's

[billstewart]

Some applications care about having nearly 1.5 volts, and this device will make a disposable battery last a lot longer for them; I've had a few electronic or electro-mechanical devices that got grumpy about only getting 1.2 volts from NiMH, so I asked these guys about it.

Their response was that it'll boost the voltage just fine, but may be bad for the battery's life, because they really don't like being drained too low, and the Batteriser is designed to suck every bit of power it can out of a disposable battery, not to treat a rechargeable battery nicely.

Lithium-Ion batteries are even more picky, and need special control circuitry that'll cut off the power if the battery's voltage gets too low (and also cut off charging if it gets too high.) NiMH aren't as picky about it, but you can still shorten their useful life a lot if you mistreat them; back when I was using a lot of them, I'd typically only get 5-10 full charge/discharge cycles from one if I wasn't careful. They could make a model that worked with NiMH if they wanted too, but it'd probably cost them a few cents more in circuitry, and they're trying to make a low-cost retail device.

The best solution I found to that problem was Nickel-Zinc rechargeable batteries, which have a chemistry that puts out 1.6 volts, so almost all of the devices that are picky about voltage are really happy with them, and capacity was similar to NiMH. Unfortunately, they seem to have disappeared from the market a bit after I bought the first batch of them, or at least Fry's stopped carrying them.

bow down

[gzuckier]

I for one welcome our new overlord, the Joule Thief. http://www.bigclive.com/joule....

Re:Lots of negative nancies in here

[gzuckier]

Gotta love context-free quotes!!

http://www.snopes.com/quotes/k...

[That interpretation of my comment] is, of course, ridiculous because the business we were in was making PCs, and almost from the start I had them at home and my wife played Scrabble with time-sharing machines, and my sixth-grade son was networking the MIT computers and the DEC computers together, hopefully without doing mischief, using the computers I had at home. Home computers were a natural continuum of the "personal computers" that people had at work, in the laboratory, in the military.

Following this sidepath... it's similar to the original concepts of home electric motors, which was not considered worth doing until electric illumination brought electricity home. If you look at the first sketches, ads, etc. for the concept they had a huge motor in the basement running everything via a series of belts and gears and shafts, analogous to Olsen's big computer running the whole house. In practice, of course, that wasn't as useful as little dedicated motors everywhere embedded in the gadgets so you don't think of them as motors explicitly, analogous to the small dedicated computers he saw coming.

Rechargeables

[MoarSauce123]

This would be awesome for rechargeable batteries, especially AA. I have a bunch of them and plenty of devices outright reject to work with them even when they are fully loaded.