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Batteries Continue To Suck
pvt_medic writes "As technology continues to grow, and we see more and more of a shift to portable electronic devices in our daily life, we are still constricted by one simple thing: Batteries. Newsweek has an interesting article about the lack of development in battery technology. 'Ironically, in our headlong rush to create sophisticated untethered computing, the most problematic technology turns out also to be the oldest: those nondescript metal cylinders that never seemed to be included with our Christmas toys.' And for those of you who would like an extensive overview about batteries, ExtremeTech.com has a nice overview."
Alkalines have high internal resistance, which makes them poor candidates for cameras and other high-current applications. Alkalines rule for transistor radios, etc, where you have miniscule current draw.
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A few years ago I got to meet with some folks from Eveready and a number of charge controller companies, and trust me, there's quite a bit of R&D that goes on.
For disposables, consider that we've gone from carbon-zinc to alkaline to lithium chemistries. In the case of Eveready, they have the L91 lithium AA, and it's pretty amazing in terms of power density and battery life (about 3X alkaline.) It's now about 10 years old.
Rechargables have gone from lead-acid to Nickel-Cadmium to Nickel Metal Hydride and also Lithium-Ion.
Keep in mind we're talking about a chemical device here that's storing larger and larger amounts of energy as times goes on. More energy = more potential for bad things to happen. Since it's chemical we're dealing with chemistry, materials science, and environmental factors (heat/cold, issues of outgassing, etc.) There's a lot more going on than a simple metal tube here.
A lot of the work that goes on is hidden -- it's hidden in the fact that the battery works for more than a few cycles. Many battery chemistries are very touchy when it comes to repeated cycling, for example, while others if not formulated (or charged) correctly would outgas or swell and explode. If any of you remember the good old days of carbon-zinc, it was routine to have things destroyed by leaking cells. That's one of the reasons the battery manufacturers actually offer warranties on the devices using them. (Think about that: It's like Exxon giving you a warranty on your engine if the gas harms it.)
While the future is probably fuel cells (I'd bet on methanol cells in particular, perhaps like Neah Power is working on) it'd be wrong to think that batteries aren't improving -- or that they won't be around for a long, long time.
1. If there was a chemical reaction that could produce energy on the nuclear level, it would disrupt nuclear processes - So whatever elements it happened between would transmute each other on contact. Look around. Do you see any natural element below the radioactive ones on the periodic table that is undergoing alchemical style (i.e. lead to gold style) transmutation to another element? No? Then there is a peak limit for how much power you can get out of any chemical battery, and it's lower than the weakest natural nuclear reactions observed. 2. The most electromotive elements are the reactive metals, like Potassium, Calcium, and Sodium at one end, and Florine and Clorine at the other. The reactive metals burn on contact with cold water, and the problems with handling the reactive gasses are legion. Batteries generally work with an anode and a cathode of two different mentals or metal compounds. Electrodes are generally made from metals in the middle of the electromotive range, like Pb, Cd, Cu, Ni, and even Hg, and their compounds. To get better energy storage per weight than zinc, nickel or cadmium just about always means working with something more reactive for at least one electrode. So "better" batteries are generally more environmentally damageing, or pose bigger health risks to humans working with them. 3. There is a metal with electromotility better than oxygen or clorine gas. It's called Gold. Unfortunately it is hard to get gold to react with chemicals, it's heavy, and it's just a touch expensive.
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Try the local hobby shop, or look for one of these. You can easily charged old ni-cads or NiMh batteries in less than an hour using a 'peak detecting' charger like that. Overnite chargers run at .1C or less (C = battery amp hour capacity) and can be left on w/o overheating. The fast chargers blast 'em with 1 or 2C which works, as long as you cut it off when they are charged or they overhead and get damaged. The 'peak detecting' chargers can tell when the battery is full and automatically shuts off. Works great.
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Actually, the greatest (and most under rated) inventor in western history, Nikola Tesla, has already created it. For some unknown reason, J.P. Morgan refused to back it.
1) Energy in a given space has nothing to do with exploding. TNT doesnt explode without a detonator, Plutonium needs a critical mass and a neutron source, etc etc.
2) Since the original electricity is a trivial cost of batteries, the question is how much energy we can keep in the battery, not how much we use to get it there, so this is utterly irrelevant.
3) Vacuums apply to pressures, not energies. Have you seen the sun exploding lately because it's more energetic than the surrounding vacuum? (No, sorry, flares dont count.)
Real problem with batteries: inorganic chemistry hasn't made any huge progress lately.
Solution: capacitors. GM is planning to use them instead of car batteries in the relatively near future.
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This one is the Shimano NX-30, and it will power a 6 watt front headlight.
Maybe not as bright as your old 10-Watt, and sure, there is a little drag, but it's not bad, and you get to stop charging your bike lights for good. And $60 for the functionality of a battery *and* a front hub is a good deal.
spreer
Actually, the battery is now believed to be much, much older.
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Having just attended a Canadian Forces Naval briefing on this very topic, I'm glad you asked :).
Naval subs use massive "wet" batteries, something akin to what your car uses, except exceptionally massive, typically filling two large-ish rooms. They are exceptionally heavy.
Note that diesel-electric submarines are only rated to run for aat most two weeks between charges. They have to surface to run their diesel engines in order to recharge their batteries, as the diesel engines need clean air for the combustion, and need to be able to vent their exhaust gasses.
This is a disadvantage over nuclear submarines, which can stay down for months at a time. The benifit of them, however, is that diesel-electric subs are quite a bit more silent than their nuclear counterparts :).
Yaz.
I find that my 1950 mAh NiMH rechargeables last longer on each charge (> 10 hours) than brand-name alkalines, let alone the Sorny versions that choke after a few hours in my mp3 player. You can probably pick up a charger and 4-8 battaries for $30-40. For me it paid for itself in a matter of weeks, and I don't constantly find myself without batteries for my walk home.
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The advances are there but people aren't willing to pay for them. Err, rather, the manufacturers don't offer the advanced batteries because they don't believe that people will pay for them.
Most laptops use Li-Ion - a technology that brings the term "suck" to the title of this article. Li-Ion sucks. Not the other technologies out there. They aren't offfered.
NiMH is a decidedly better technology. Matsushita (who, BTW, is currently in arbitration with Ovonic Battery over a patent dispute) has brought the new Toyota Prius battery up to some astounding levels of power and energy density. And the batteries are proven to last for the vehicles lifetime - not this puny 500 cycles like Li-Ion that we get with laptop batteries. Didja ever wonder why your laptop's 2-year warranty didn't include the battery?
Because margins are already too thin. They can't afford real battery technology. We'll have true wireless only when the electronics downsize their power requirements.
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What happened to the super capacitors? You know, caps with such a high energy density that they could be used to replace batteries in many applications.
Nonsense.
1 Farad = 1 Amp at 1 Volt for 1 Second
As anyone who knows capacitors can tell you, a farad is a huge unit. To put things in perspective, common, everyday capacitors often have capacitances measured in picofarads (a picofarad is one-thousandth of one-billionth of a farad).
Now, how much capacitance would it take to equal a single AA battery?
A typical AA battery might be rated at 2200mAH at 1.5V. It doesn't actually keep that voltage up the entire time, but let's just pretend that it does.
2200mAH = 2.2AH = 7920As
So, a typical AA battery delivers 7,920 amp-seconds at 1.5V. An equivalent capacitor would need to have a capacitance of around 11,880 farads. That's to equal ONE AA battery. No such capacitor exists, and even if one did, it would be absurdly dangerous to handle.
The strength of a capacitor is its ability to deliver its power very, very quickly. That's why a big capacitor would be so dangerous -- imagine discharging all of the power in a AA battery in a ten-thousand of a second. The strength of a battery, on the other hand, is its ability to deliver (relatively) unbelievable amounts of power, but it can only do so over much longer periods of time.
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http://electronics.howstuffworks.com/capacitor.htm
Actually, the "memory effect" thing is a myth. What really happens with multi-cell nicad packs is one or more of the cells runs down to 0 volts before the rest do and subsequently gets "anti-charged" by the other batteries in the pack. The reverse voltage damages that particular cell, reducing its capacity. A multi-cell pack only gives full voltage for as long as the weakest cell in the pack can. The weird thing about the "battery memory" thing is that the recommended means of avoiding problems (full discharge before recharging) is more likely to result in cell damage. Then again, the difference between that and the opposite (recharge frequently without discharging) is practically nil: nicads are just crap.
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Note that you can also charge such subs while in dock, by running cabling to a charge port (no kidding!).
Obviously, you need to pick and choose what types of missions you use such subs for. As I mentioned, they aren't for long-duration underwater missions. They serve a different purpose than nuclear subs serve.
And BTW, the Canadian Forces routinely detects the US Los Angles-class nuclear subs while they're supposedly running in "quiet" mode :).
Yaz.
Yes, reactors are noisy relative to batteries. They have hot fluids being pumped around in heat exchangers and driving generating turbines.
Maybe I've just grown overly cautious in my old age, but if it can be charged quickly, it must capable of discharging quickly, no? Energy-storage devices of reasonable density that can discharge very quickly make me nervous about bad things happening. Maybe not on the order of your gas tank "discharging" suddenly, but certainly the possibility of heating conductors enough to start a fire.
When you switch one on, the tungsten filament is still cold, and - like most metals - the resistance of the filament is lower at lower temperatures.
This is what causes a major surge in amperage, and this is what actually 'breaks' the filament. The cold period lasts only a split second, but this is enough to fry a weak spot in the filament.
The weak spots are formed during 'normal' use, since it is virtually impossible to create a wire with even with along its entire length. A part that is only marginally thinner than the rest, will have higher resistance and hence voltage drop and power dissipation than the rest of the wire. This higher temperature will cause the tungsten to evaporate faster, and condense slower, on the already weak part of the filament - causing the weakness to get weaker until in eventually poops out under start-up conditions.
The funny thing is: some ordinary bulbs can run for decades continously, but don't even think of switching them off and on after that!
That bit about NiCd batteries having "memory" but not NiMH? Not true. Yeah, they got the crystalization part right, but they ignored the usual cause. Too many people (manufacturers and users) used dumb chargers and overcharged the batteries causing them to release hydrogen and oxygen. The resulting charge/discharge curve led people to think this was the memory effect, when it really wasn't.
Battery chargers today are much more sensitive to the charge state of a battery and as a result they're much less likely to overcharge a battery.
According to the GE manual on NiCd batteries, there really is a "memory effect" on NiCd batteries, but it relates to their use on board spacecraft in orbit where charge and discharge cycles are very regular. This effect is slightly different from that which results from overcharging the pack. Most people don't charge and discharge their battery packs so regularly.
In the case of the batteries in orbit, the full capacity can be restored by one or two irregular charge/discharge cycles. However in the case where you overcharge the batteries, you actually lose capacity in the battery.
By the way, overcharging a NiCd battery is less damaging than overcharing a NiMH battery. The former can recover some of it's capacity by exposure to air to recover the hydrogen and oxygen gasses it released, but the latter generally doesn't.
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