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OP is conflating cycle life with deep cycle life. Li-ion batteries typically only last about 300-500 deep cycles (full charge to full discharge back to full charge). But by limiting the operating range (say, between 20%-80% of a full charge, which is what most EVs do), you can avoid the deep cycles and lengthen battery endurance considerably. That's how EVs are managing to go 10+ years on the same battery pack. Most of the automakers limit the battery's operating charge between 25%-75% or 20%-80%. Tesla is hush hush about their numbers, but it seems to be between 15%-85%. (This is why they could give owners additional range during hurricane evacuations - they simply sent out a temporary software patch allowing you to drain the battery below 15%.)

The drawback of using only partial discharges is that you need significantly more battery capacity than you're actually using. Consequently, the cost of using batteries for load leveling is highly dependent on the variability in how much load leveling is needed day-to-day. If the same amount of power needs to be time-shifted every day, that's the ideal case. If the amount of power you need to time-shift varies by a lot (a little to none one day, close to max the next day), you end up having to pay for a huge battery but use only a tiny bit of its capacity most of its capacity most of the time

This is different from something like pumped storage (pumping water uphill), where the bulk of the cost is in the pump and turbine, while reservoir capacity is nearly free. With batteries, most of your cost is in the capacity, so it ends up being price-sensitive to variability in required capacity. From what I understand, Tesla picked this location partly because of the consistency of the capacity shortfall/excess.

This is technically your fault

What utter bullshit. It is the fault of Apple's engineering, that can't safely trickle charge a li-ion battery. I have lots of devices permanently sitting on chargers, everybody does. But don't do that with Apple products unless your fire insurance is all paid up. According to you.

but the knowledge of how to keep a battery stored really matters and isn't very common knowledge. Any device with a lithium-ion battery of any kind should not be left on the charger for extended periods, like days or more. If you plan on not using the device, unplug and turn it off. The protection chip on the battery will prevent overcharging but it's a precarious situation that might cause overheating, swelling and explosions potentially the longer it's left charging.

That is true if you buy from Apple, apparently.

Citation and more details: https://batteryuniversity.com/...

Your link doesn't say anything like you just claimed. Are you an Apple employee?

Bullshit:

https://discussions.apple.com/...

This is technically your fault but the knowledge of how to keep a battery stored really matters and isn't very common knowledge. Any device with a lithium-ion battery of any kind should not be left on the charger for extended periods, like days or more. If you plan on not using the device, unplug and turn it off. The protection chip on the battery will prevent overcharging but it's a precarious situation that might cause overheating, swelling and explosions potentially the longer it's left charging. Citation and more details: https://batteryuniversity.com/...

Apple claims iPads don't overcharge, period. I think the GP is lying.

https://discussions.apple.com/...

This is technically your fault

What utter bullshit. It is the fault of Apple's engineering, that can't safely trickle charge a li-ion battery. I have lots of devices permanently sitting on chargers, everybody does. But don't do that with Apple products unless your fire insurance is all paid up. According to you.

but the knowledge of how to keep a battery stored really matters and isn't very common knowledge. Any device with a lithium-ion battery of any kind should not be left on the charger for extended periods, like days or more. If you plan on not using the device, unplug and turn it off. The protection chip on the battery will prevent overcharging but it's a precarious situation that might cause overheating, swelling and explosions potentially the longer it's left charging.

That is true if you buy from Apple, apparently.

Citation and more details: https://batteryuniversity.com/...

Your link doesn't say anything like you just claimed. Are you an Apple employee?

This is technically your fault but the knowledge of how to keep a battery stored really matters and isn't very common knowledge. Any device with a lithium-ion battery of any kind should not be left on the charger for extended periods, like days or more. If you plan on not using the device, unplug and turn it off. The protection chip on the battery will prevent overcharging but it's a precarious situation that might cause overheating, swelling and explosions potentially the longer it's left charging. Citation and more details: https://batteryuniversity.com/...

Typically, a "cycle" is defined as discharging to 0% and recharging to 100%. Partial charges and discharges (e.g. you notice battery is getting low so you charge it at 20%, then take it off the charger at 80% because you figure that's enough to get through the rest of the day) are much less stressful, and your battery can survive a lot more of those partial cycles. That's the strategy employed by EV makers to maximize battery longevity.

Where are you getting your figures? Because the last time I looked at this, Lithium batteries are around 99% efficient.
http://batteryuniversity.com/l...

and no, an electric drivetrain has only a small advantage over an IC drivetrain

BEV vehicles are far more energy efficient than ICE vehicles because the ICEs are at best 30% efficient. And then there is regeneration.

Sorry, facts are so inconvenient, aint they..

Yes, but it would be nice if you included some actual facts in your post.

Tesla is able to get only 5% decrease in capacity over 1200 cycles

You can get figures like that if you use very shallow depth of discharge. Say, 10%. The drawback of course is you then need to buy a battery whose capacity is 10x greater than the max charge you plan to regularly use, thus driving up cost 10x. Which is pretty substantial when the battery is already the most expensive part of your system.

The problem is due to the physical distortion of the battery as it's charged. The greater the cycle depth, the greater the distortion, and the more quickly it wears out.

https://en.wikipedia.org/wiki/...
Neither the first nor second law has anything to do with electricity (none of them has)
The laws of thermodynamics are about stream engines (I simplified it a bit for you), or in other words: idealized gases under heat an pressure.

Or if you need more:
https://courses.lumenlearning....
The Wikipedia article unfortunately regularly gets rewritten in an incomprehensible state and then fixed again :D

http://batteryuniversity.com/l...
Efficiency of lithium ion batteries is about 99%.
Probably some idiot edited the your wikipedia article?
On the other hand some other idiot could have edited the thermodynamics article to my favour :P

Your pick ....

This means when you charge the thing, there is entropy gain, as you convert energy from one form to another
Wow, another stupid argument.
There is no entropy gain when you charge a battery. You reduce entropy.
Uncharged battery: everything is chaotic distributed.
Charged battery: everything is fine sorted, all charged particles on one side.

Imagine a class of water, drop a sugar cube into it. Low entropy: everything sorted. The cube is in one corner. The rest is clean water. When the cube is gone: high entropy. It is distributed all over the place. With a "gradient" of sugar concentration which is high at the spot the cube was, and the lowest at the most far away spots in the glass. Recharging the cube to its old position: removing the entropy.

Good luck with your half knowledge of Physics (and physics is probably the most simple natural science, until you hit Quantum Mechanics, Relativity Theory and/or String Theory)

I hope for you, that you are never in a life threatening situation were some basic understanding of physics would save your life, and you fail.

Regarding that wikipedia article, it seems that specific battery they used as an example has 80% - 90% efficiency. However that sounds not plausible to me.
The Li-ion batteries in a car have close to 99% efficience. With charging equipment etc. that drops to 95% - 957% ... google is your friend.

More information:
http://batteryuniversity.com/l...

Look at tables 2 and 3.

"Similar to a mechanical device that wears out faster with heavy use, the depth of discharge (DoD) determines the cycle count of the battery. The smaller the discharge (low DoD), the longer the battery will last. If at all possible, avoid full discharges and charge the battery more often between uses. Partial discharge on Li-ion is fine. There is no memory and the battery does not need periodic full discharge cycles to prolong life."

http://batteryuniversity.com/l...

The linked page includes a chart showing the relationship between depth of discharge and number of charge cycles. If I were to guess I imagine electric car drivers are charging daily/nightly when the car is parked at home and just leaving it on the charger when it is in the garage, even though they might have over 50% capacity remaining. Similar to smartphone users who are in the habit of plugging the phone in to charge when they are in the car or sleeping.

"I see for most lithium battery technology is usually around 500 cycles."

Most devices with Lithium batteries are only expected to last a few years and the important factor is how long the device can run per charge so they tend to use all the capacity. A battery that is charged to 100% will die before one that is charged to less than full capacity. A car should last at least 10 years and the manufacturers have left headroom in their batteries for longevity so when the car reports the battery is at 100% it actually isn't but is more like 80%. Same goes at the other end where there's likely around 20% still left when the car says the battery is flat. Sure, if the car used the whole capacity of the battery like a phone does it would be able to go further on a single charge but it would also degrade rapidly and within a year or so the range would be significantly diminished and by year 3 the battery would pretty much require replacement. Useful info on this page: http://batteryuniversity.com/l...

This problem (after a few years, battery life being half what it was when new) has pretty much been solved with larger battery capacities and lower power components. Lithium-ion batteries do degrade this way based on the number of charge/discharge cycles. But the depth of discharge matters more. A battery which will only last 300+ cycles when charged to 100% and discharged until dead, can last 1200+ cycles when charged to 75% and discharged to just 25% before being recharged. The relationship is non-linear - reducing the cycle depth by half results in about triple the battery longevity. So it isn't just a matter of shallower discharges using the battery less. In other words, the worst thing you can do to the battery is to charge it all the way to 100% and discharge it all the way to 0%.

Most newer batteries integrate this into their design. When they report 100%, the battery is actually at 80% or 90%. When they report 0%, the battery is actually at 10% or 20%. The Li-ion battery packs in EVs are a good example - they're limited between 20%-80% charge, or 15%-85% charge. Many laptops also add software which further limits the charge - stopping the recharge process when the battery reads 80% or 90% (which probably corresponds to 65% - 80% of the battery's real capacity). Couple this with the user making sure s/he never discharges the device completely, and you've eliminated the deep charge/discharge cycles which degrade the battery the most.

In the old days, laptops used a lot of power and batteries were bulky. So manufacturers had to use 100% of the battery's capacity just to eek out 2-3 hour battery lives. This is what led to many of those batteries dying after a few years. Nowadays, battery energy density has improved, and mobile electronics use a lot less power. So manufacturers can put in a small or medium-sized battery in a laptop and still get 5-8 hours using only 60%-80% of the battery's capacity. So they've taken advantage of this to replace the swappable battery with an integrated battery and cut down on weight and size. The charging circuitry limits it so it can't actually charge to 100% or discharge to 0%, thus allowing these integrated batteries to be used for well over 1000 cycles - usually more than enough to last the lifetime of the device.

If the indicated battery percentage jumps wildly between charging and discharging, it may simply be that the battery gauge needs to be recalibrated. Especially if battery diagnostics don't show anything wrong.

http://batteryuniversity.com/l...

Current Li-ion batteries only have about twice the energy density of NiCds. The reputation NiCds got for having lousy energy capacity was due to a memory effect. If you kept recharging the battery before it had been fully discharged, it "learned" the low charge state as its new zero state, and you lost that bottom portion of its capacity (due to crystalline growth).

Rechargeable batteries have increased about 2x in energy density in the last half century, and about 3.5x in the last century (from lead-acid to li-ion). So claims of a 10x increase in the near future are going to be met with a lot of skepticism.

There's more to it than a removable batteries simply being unpopular. Lithium-ion batteries have a shallower voltage curve than other rechargeable battery chemistries. That is, the voltage does not change that much as you discharge or charge the battery. This makes it trickier to detect how much remaining charge there is, and when the battery is at full charge. Doubly so when you add in voltage depression due to load, and elevation due to the device being charged. Add in Li-ion's tendency to experience thermal runaway when overcharged, or over-discharged then recharged, and getting the charging mechanism just right is critical but requires very precise knowledge of both the battery, and how much current the device draws.

Removable batteries throws a big monkey wrench into all this. Now suddenly the battery that's put into the device may not be the same as the charging mechanism was originally designed to work with. So you have to make the charging mechanism flexible enough to deal with all the different batteries which might end up being plugged into it.

I totally disagree with you that removable batteries are unpopular. If two devices with identical form and functionality, but one with a slightly smaller removable battery, were sold side-by-side, IMHO the removable battery model would far outsell the fixed battery model. But manufacturers are going with fixed batteries simply because they're easier to design, and because it helps reduce their exposure to liability (In the early days, cell phone makers were sued when their phones caught fire, but it turned out most of these people had replaced their original battery with a cheap Chinese knockoff).

Your batteries seem to weight about twice as much as my cell phone batteries per Wh. They are however much, much more powerful.
It seems to match a phosphate or manganese chemistry rather than the more common and more energy dense cobalt. I am no expert though.

See : http://batteryuniversity.com/l...

The problem is, the aggressive charge/discharge cycle is what's giving these batteries a competitive energy density compared to other battery chemistry and other energy storage solutions.

I'm gonna go out on a limb and predict that the solution will be to partition the two reactants in the battery chemistry with something more than a 24 micrometer separator. Possibly even switch to a chemistry which doesn't require carrying around one of the reactants at all, and getting it from the air. You know, like gasoline needs oxygen from the air to release its energy, so as long as you keep it in a sealed tank a fire is virtually impossible.

But label the 80% charge "100" and the 100% level as 120 (no percentages)

Or 125, because 100 is 25% more than 80.

It would also be good to have a "storage charge" feature which keeps it charged at 40-50%, for battery powered devices that you leave plugged in most of the time, like laptop workstations.

Also, there have been no battery fires, but aluminum feels pretty hot when it gets to 50C and people assumed their phones must be OMG about to CATCH FIRE!!

Not sure what Apple fanblog has been spreading that nonsense. Anyone familiar with Lithium-ion chemistry can tell you unequivocally that charged Li-ion batteries can catch fire when damaged or overcharged. You'd be a fool to dismiss it as anti-Apple rhetoric - click on related links to other brand Li-ion batteries catching fire if you feel this is somehow singling out Apple. They're all dangerous and need to be treated with respect for the potential damage they can do. It's why the FAA has banned them in checked baggage on passenger airliners (not that the passenger cabin is much better, but at least there are people there who will immediately notice the fire and try to put it out).

From http://batteryuniversity.com/l... (I looked it up because I was thinking the same as you did):

"If the fire occurs in an airplane, the FAA instructs flight attendants to use water or pop soda. Water-based products are most readily available and are appropriate since Li-ion contains very little lithium metal that would react with water. Water also cools the adjacent area and prevents the fire from spreading. Many research laboratories and factories also use water to put out Li-ion battery fires."

This doesn't work on Lithium Metal batteries, so:

"When encountering a fire with a lithium-metal battery, only use a Class D extinguisher as water would react with the lithium metal and make the fire worse. With all battery fires, allow ample of ventilation while the battery burns itself out."

I translate that as "fumes will still kill every passenger on board, but at least we can recover the bodies."

The cost of cycling an EV battery is about 50 cents per kWh (source). In many cases, electricity from the grid is far cheaper than that from the battery, even when the battery can be charged for free.

Assuming that Tesla can cut that cost in half, things start to get interesting. It would then make sense to use the battery whenever the difference between what you pay for electricity and what you can get for it is less than 25 cents (plus a few cents to account for losses in the battery). But the profit, if any, would be small, and the initial investment is high.

I don't think that anybody who is on the grid today will benefit from going off it. This technology currently only makes sense for new construction in remote areas. But maybe a decade from now, prices will have come down, and there will be a huge market for this. Tesla will then have a big share of that market.

It isn't a good idea to completely deplete a lithium-ion battery on a regular basis. Keeping its charge above 25% makes makes an 18-hour battery a 13.5-hour battery, which means it must be charged 1.8 times a day, unless you charge it overnight while you sleep.

Still, its battery life is a step back from conventional watches. If you're going to invent a new mousetrap, you should try to make it at least as good as the old one in every way--no regressions.

You don't think Apple are quoting the usable life of the battery?

That buffer zone is already included in the battery's charge controller. When it says "0%" it isn't really at 0%.

It isn't a good idea to completely deplete a lithium-ion battery on a regular basis. Keeping its charge above 25% makes makes an 18-hour battery a 13.5-hour battery, which means it must be charged 1.8 times a day, unless you charge it overnight while you sleep.

Still, its battery life is a step back from conventional watches. If you're going to invent a new mousetrap, you should try to make it at least as good as the old one in every way--no regressions.

This is not really about the use of Lion batteries. So Facebook is going to change out lead-acid systems that give ~20-30 minutes (MY guess, TFA does not say) to one that gives only 90 seconds for generator start.

That 'dragster' remark is cute but it falls flat with me. There is a whole class of real-world fail opened up here. 90 seconds is scarcely enough time for humans to respond, let alone diagnose and solve a problem. As a critical infrastructure IT admin I'd never want to commit to this. It is an example of one of those 'Faustian bargain' compromises over time that are making modern technology fragile (in a sneaky way that is no one's fault) , where the UPS maintainers are 'absolved' of responsibility for the Big Fail when it happens. Blame is shifted onto the generator maintainers --- who might have been able to solve the problem had they had more than 90 seconds in which to do so.

Not to mention that lead-acid batteries are mostly water and non-combustible sulfuric acid. A Li-Ion battery fire is 50 times nastier than a lead-acid battery fire, and produces a hell of a lot more noxious gases.

If you design a commercial class server farm without a physical fire/vapor room/wall between batteries and servers and a real DC bus you have already lost the battle, abandoned Bell Standard Practice. I remember when telling someone they were violating BSP was the worst thing you could say. Now it's like, "Bell Standard Practice? What's that? Look it's cool, we just unpack this stuff from the box, snap it together and it works!" Until it doesn't. Or a single battery catches fire and you have to clear the room and don moon suits.

There are other issues too. It's an environmental loser. If you're championing Lion over lead acid for vehicles you're a winner because there is no other way. But this move to install Lion over lead-acid in places where the additional sqft is available is silly. Lead acid maintenance and recycling is a no-brainer. But Lion? Taks a look at this article on state-of-the-art battery hazards and recycling. "it takes 6 to 10 times more energy to reclaim metals from some recycled batteries than it does to produce it through other means, including mining" and thus only a few companies are doing it, probably living on subsidy. The Lion boom is driven by China's rare earth industry, and you can be sure they'll turn the screws when assimilation is complete. There are even some who claim that due to economic reality, many Lion batteries, even the heavy duty ones, are dangerously destined for the landfill, a place lead-acid batteries do not go because their recycle process is mature and chemically simple.

So from here it really looks like Facebook is trying to eliminate a few blue-collar battery maintainer positions in their Data Center, at great cost, to their ultimate peril. Never mind that extra time to keep servers running while you fix faults, just chuck the old stuff, install these things, and... relax. The Big Fail will be no one's fault because the accountants have signed off on it.

Story of the modern world.

I found some info on it. BU-1205: Availability of Lithium http://batteryuniversity.com/l...

Store your spare li-ion batteries with a half charge

And at 0 degrees C.

So... not to stir up a hornets nest... but everyones aware that electric cars produce more pollution than gas right?

Let's look at some facts here. First off, the efficiency of a thermal power plant is somewhere around 33% to 48%, at least according to wikipedia. Let's split the difference and say 41% for a thermal plant. The typical thermal efficiency of a a gasoline engine is about 18% to 20%. Let's split the difference and say 19%. Thus, a thermal power plant is more than twice as efficient as a gasoline engine in terms of changing chemical potential energy to useful output.

But there are some caveats. Firstly, the electricity needs to be transmitted. High voltage power lines are extremely efficient, about 94% according to this article. That means that the chemical energy (lets assume from coal) reaching the charging station is 41% x 94% = 38.5%. And then there is the charging process. According to this article, the charge efficiency of a Li-Ion battery is about 97%, which makes sense to me, as batteries usually don't run too hot. The charging devices however probably are responsible for some loss. Let's assume they are 80% efficient. That gives us 38.5% x 80.0% x 97% = 30%. Thus, according to this, 30% of the coal chemical potential energy makes it to the engine.

But what about engine efficiency? Well electric motors run very cool, and have very high efficiencies, typically around 90%. I wouldn't be surprised if Tesla's motor is better. This means that if a coal power plant powered a Tesla, 30% x 90% = 27% of the energy would reach the wheels of the car, compared with a gasoline powered car, where 19% of the gasoline's potential energy comes out of the engine, never mind the losses in the transmission lines. Thus, a coal powered Tesla is 40% more energy efficient than a gasoline powered car.

However, there is one problem. Generating energy by coal produces more CO2 than generating it by gasoline. According to this article, coal generates about 215 pounds CO2 per btu of energy, while gasoline generates 157 pounds CO2 per btu. However, even with this, by my calculations, an equivalent gas powered car still emits 3.8% more CO2 than our coal powered Tesla.

Elon Musk made this claim in an interview, that even if a coal power plant generates the electricity, a Tesla still emits less CO2. My referenced back of a napkin calculations above support this assertion.

You laugh, but apparently crude hybrid is a thing.

Batteries have gone through multiple generations of technology in the last two decades. Solar panels are now so cheap that the physical installation costs are the biggest part of installed costs. Solid-state storage is increasingly the norm. OLEDs are now in TVs, 77" diag. 4k-ish, WRGB. e-Paper readers cost tens of dollars and are seen as outdated tech. Smartphones cost tens of dollars. 4G phones. Gb/s Wi-Fi. Etc etc.

How much fucking progress do you need?

(When Li-Ion was introduced in '91, it stored less than 90 Wh/kg, now it's over 200 Wh/kg. The price was over $3/Wh, and is now less than 30c/Wh. http://www.batteryuniversity.com/images/parttwo-55h.gif. And there's no reason to suspect it will stop, we're still pushing Li-polymer capacity. With LiS, LiMetal, and ZnAir all in the early commercialisation stage, and graphite-everything in the lab stage.)

((Solar panels have doubled in capacity/m^2 every ten years, and halved in price/m^2. Every doubling of global production cuts the price by 1/5th. http://www.economist.com/blogs/graphicdetail/2012/12/daily-chart-19. And there's no reason to suggest the trend will stop.))

Lead Acid batteries hate trickle current.

Citation? I know they've been increasing the size of batteries and chargers in modern cars to keep up with the increase in vampire draw from all the electronic do-dads, I also know that lead acid batteries don't like being fully discharged, but I've never heard the trickle current thing.

As for the secondary batteries, with cars lasting over a decade I'd really rather not have to replace more batteries.

No. Depth of discharge is significant for battery wear. Going 80 % -30 % twice is not the same as going 100 % - 0 % once. Note that laboratory tests on batteries are based on 100-0 % cycles that are deeper than what the car allows. An "empty" battery is not at 0 % SOC. There is a buffer in the bottom and probably at the top too. Look here.

I assume that means non-user-replaceable. People need to stop buying devices with non-replaceable batteries, or that's all that will be available before long.

Given that Lithium Ion loses capacity over time AND with discharge cycles, it is essential that batteries be replaceable to prolong the lifetime of the device without having to pay out the nose for the mfg to replace the battery. Also, this allows easy swapping of batteries in the field if you have to be away from a charger for an extended period, and it often goes hand in hand with being able to swap micro-SD cards.

Just stop buying them, and mfg will get the message.

That doesn't change the details of what a charge cycle is versus what you tried to explain. Here's a good explanation of Lithium battery life.

If you check batteryuniversity.com, one of the points made is that battery life can be prolonged by not charging the battery to 100%, but instead to lower voltages (i.e. only charging to 90% capacity. The lower the voltage, the more life you get out of the battery. So it could actually be that, if Apple is tweaking the cutoff point of its batteries to get better battery life, it's on the top end -- not the bottom.

How to Prolong Lithium-based Batteries

Of note, this is one reason I still love Thinkpads: their Power Manager software allows you to set the maximum charge point, so you can set it to charge only up to 95% (or whatever you want) and it will do this even when rebooting into Linux, though the software must be run under Windows, of course.

can be found at http://batteryuniversity.com/learn/

Without knowing how deep the cycle was. Furthermore, the rate of discharge and temperature during the discharge will also have a fairly significant affect.

Basically, you will get about 1/10th the charge cycles out of a battery that is nearly completely discharged vs one that is only discharged to 10%.

Its better to really think of LI as providing a fixed number of watt hours. You can consume them in small bites, or you can consume them in big chunks but once you consume them they are gone.

The best rule for laptops is carry the charger and use it when at all possible.

Oh, and don't buy machines without replaceable batteries. If the "average" user can get 3 years out of it, and you decide your going to use all 8 hours of battery life every day, and charge it at night, you will probably be lucky if it lasts a year.

Plus, if your laptop gets hot (either by being left somewhere hot, or because of poor cooling) then the battery life is going to nose dive even if your plugged in. If your going to be doing a lot of intense gaming, your probably better taking the battery off and placing it somewhere cool (just don't let it discharge).

See this link http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

Li-ion is 97 to 99% efficient. Your point was?

No, it is a function of the battery chemistry. You have LiCoO2, LiMn2O4, LiFePO4, and others, each with different charge voltages. A good read: http://batteryuniversity.com/learn/article/types_of_lithium_ion

Capacitors much like batteries don't store "voltage" they store electrical charge (basically electrons), ampere seconds.
Regular cell phone batteries have a charge of about 2Ah, assuming this super-capacitor will have a similar charge and remembering that a capacitor can be discharged at least as fast as it can be charged, in 20 seconds or less, this could create an average current of 360 ampere, give or take a few ampere. Given the nature of the current flow when discharging a capacitor the current will be twice as high in the first few seconds of discharging at about at least 700 ampere.

And that's no laughing matter anymore.

This article says that' their cell voltage is between 2.3 and 2.75V. Lets assume a value in the middle of 2.5V.
-> Capacity: C=Q/U=(7200As)/(2.5V)=2800F (!!!)
-> Electrical Energy: E=0.5*C*U=.5*2800F*(2.5V)=1400(As/V)*6.25V=8750AVs=8750J

Granted, these numbers are quite speculative because I lack the exact specifications, but it should give you a rough estimate of the numbers we're dealing with here.

Haha, awesome... "Help me, owner, I'm gonna die because I can't figure out how to stop draining my battery! I don't perceive the irony of consuming battery power to display this message, either!"

Haha, they also offered the option of having the car phone home with a GPS fix in order to dispatch the emergency "help you plug in your Roadster" crews too. All these "preventative measures" they tried appear to be a brain damaged, backward, insanely complex approach compared to the obvious solution of having the system simply shed all but trivial load/total shutdown/disconnect the battery via relay (had they designed one in)/whatever during a low-charge emergency.

Which apparently they figured out eventually, because they released an update to allow the vehicle to "sleep" now, right?

According to Battery University, it seems that a lithium ion battery at 40% charge level should retain 96% of its capacity after a year of storage at 25 C. So, it seems that simply removing *all* load (including state-of-charge monitors) after the capacity gets "low" (pick a value) and there is insufficient power to charge should prevent all damage to the battery pack. The further below the ideal storage charge level of 40%, the sooner a parked vehicle without charging power should enter emergency, total shutdown. This just cannot be that hard, and should have been patently obvious to anyone designing an EV's power system.

I guess that tips the balance for Telsa in favor of incompetence instead of malice. For whatever that's worth.

The logs don't lie. The logs of that trip have been published. As the Wannabe King has already posted, Broder deliberately undercharged the car, repeatedly. The logs indicate that he intentionally sabotaged the test, so that the car would fail the tests.

Charging a Lithium-ion battery isn't like filling a gas tank. It doesn't happen linearly, especially if you're doing a high-amperage quick-charge (which is what the Supercharge is). It starts off charging quickly, but when you get to a certain point close to full you have to slow down or risk destroying the battery. The whole point of the Supercharge isn't to give you a full charge in 1 hour (which I doubt it can do without crossing this danger threshold). It's to give you approximately a half charge in half an hour. Ideally you don't want to quick-charge above maybe 80% full charge.

Which is precisely what Broder did - giving the car approx 150-200 miles in range at the two Supercharge stations. Which not so coincidentally was a little more than needed to get to the next Supercharge station. This isn't evidence of trying to sabotage the test. This is exactly how you would want to charge the car if you want to maximize distance traveled while minimizing the time spent charging and potential for battery damage. If you insist on charging the car to full at each Supercharge station, you're going to spend more time charging per distance traveled, and you're risking damaging the battery.

The disputed third charge was not at a Supercharge station. Broder claims Tesla staff told him the car would regain some of the reported range it lost while parked overnight, so he didn't need to charge until the miles remaining showed enough to get to the next Supercharge station (he spent ~45 minutes charging trying to add enough range to get to the nearest Supercharge station). Musk claims Tesla staff told him no such thing.

Streetlight, you're correct in pointing out that battery failure can occur by lead shedding causing a short or open circuit. But that's only one failure mode. Sulfation occurs when a lead acid battery is discharged too deeply. That can occur by self discharge when a battery is left to stand for a long time (10 months or so) without recharging. Here's some info:
http://batteryuniversity.com/learn/article/sulfation_and_how_to_prevent_it
The comments at the bottom of the link are interesting and include some real world results. Seems there is a bit of snake oil salesmanship in the battery additive/reconditioner industry but the pulse desulfators have been around for a while and do seem to work.

Of course, that's with a 3-cylinder economy-optimised engine. We're getting around 11 miles per litre (50-something miles per UK gallon ; I forget the conversion factor for US gallons. Are US miles the same as UK miles?)

It costs very little and takes very little to refine and smelt for. Lithium is a magnitude more intensive to mine due to its rarity and density within the ground; a lot more ore must be smelted to acquire a similar volume of metal - never mind weight.

Oh, a geology question! I'm qualified to answer those. Yes, lithium ores are fewer and further between than lead ores ; but lead itself is pretty rare too. In terms of total amounts available ... 1.1ppm for lithium ; 0.23ppm for lead (averaged over the whole Earth). 4 times as much lithium as lead. The difference is that lead is less "compatible" than lithium so is separated out from silicate minerals during magmatic processes and concentrated significantly into ore bodies. The lithium instead remains well distributed through a variety of silicate mineral structures, and only rarely concentrates to form an economically viable ore body. Off the top of my head I can only think of one mineral that has a significant lithium concentration (a mica) but there are dozens of well-characterised lead minerals - I've got a number in my rock pile.

It was news to me, but no surprise, that an increasing amount of lithium production is from processing of brines. So ultimately the processing could go down to processing seawater, if the concentrations are high enough. "Smart mining" becomes quite credible, for example a suitably tailored ion-exchange resin could pull lithium out at pretty low concentrations, requiring little more technology than a coastline and a pump. Or a suitable reverse osmosis membrane as part of a desalination plant. No pits ; no miners ; no hassles.

Lithium is roughly a 30th as dense as lead.

S.G. Li = 0.53 ; S.G. Pb = 11.34 ; ratio 21.

It is massively more expensive because of the necessity to perform all reclamation operations at -330F.

What?

I see one recycler saying that the first step of their process is to freeze the batteries in liquid nitrogen, then shred and crush them. The frozen batteries would be much more brittle than at room temperature, so you can get a finer grain size more quickly. After that ... they don't go into details, but separating by density (air current, or water current?) would be pretty high on my list of suspects. Magnetic separation too - if there's any structural iron in the powder.

The same site (there's not a lot of detail about how recycling is done) gives the cost of battery recycling as $1000 to 2000/ton (without specifying the battery chemistry), with an aspiration of $300/ton. Which is not a zero cost. But no-one I've heard has been claiming that recycling is a zero-cost option (the claims are that recycling is less expensive than dumping followed by remediation ; remediation is extremely expensive).

90% is too conservative. Brushless DC motors (the sort you'd pair with a VFD in any electric car) are pushing 96%: http://www.ti.com/ww/en/motor_drive_and_control_solutions/motor_control_type_brushless_dc_BLDC.htm. Lithium Ion battery efficiency is, depending on your source, 95% or 97-99%. So your 27% figure could be 34%. More importantly, since you have a drivetrain capable of driving the car at highway speeds in pure electric mode (something current parallel hybrids lack), a series hybrid could potentially be cheaper to operate if charged at night, and you can recoup more energy through regenerative braking.

Here is one.
Here is another.

Hate to say it, but I just got served!

  http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

Good article. I thought it was bad to keep it plugged in and good to let it run. Turns out it's the opposite!

Anyone know if the same applies for laptops?

This suggests that there's a lot to be said for not driving your battery charge down to "zero" (as defined by the battery controllers and the 3V limit). You'll get many more cycles if you avoid the extremes (full charge, full discharge).

http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

Battery University is one of the prime suspects in the crap information category. For lithium ions they claim 10% is lost in THE FIRST DAY and after that 10% a month. It's complete bullshit of course. However, since we're talking cars here, a lot of electric cars and hybrids still use nickel metal hydride, which is notorious for high self discharge. A typical nickel metal hydride does lose about 30% in 6 months. Newer low-self-discharge designs (Sanyo Eneloop) lose only 10% in 6 months.

Memory effect is however not mythical at all. Nickel cadmium batteries are crippled by it. They are basically completely unusable in real life applications. Nickel metal hydride and lithium ion do not have memory effect.

Firmware in a battery
Smart batteries are used by Apple, Lenovo, HP/Compaq, and other companies.