Technology
Replacing lithium batteries?

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MAKE pal Tom A. writes in with a bit of battery discussion regarding a recent (potential incident) with lithium batteries, he writes “Please check out (this PDF) especially the pictures of blown-up electronics. This report has some great pictures of what can go wrong with lithium batteries. Ordinary lithium batteries have 1/8 the energy density of TNT (in their electric charge alone, not counting the energy you get from burning lithium), and are headed towards 1/6.

I think the 1/8 and 1/6 energy density fractions are interesting (and inflammatory!) Here is the reference for the energy density of lithium batteries – Link.

Here is the article with the energy density of TNT – Link.

Here’s what it has to do with Makers: Can you replace the batteries in your own device?

Gadget capability is limited by the tradeoff between safety and battery energy density. Exploding counterfeit batteries make this tradeoff especially painful, which is giving rise to ‘battery authentication’ chips, that purport to establish that batteries are legit. Consumers perceive these chips as a way for a vendor to lock in a high-cost replacement battery. I paid $30 retail for a little cell phone lithium battery that I know “should cost” about $10. But it seems like they are addressing a real problem, assuring that my cell phone will not explode. Now I predict that there will be another crypto war, this time between battery authenticators and imitators. Read this article about the battery authentication chips – Link.

20 thoughts on “Replacing lithium batteries?

  1. The risk of Li-poly batteries is independent of the manufacturer to a large degree. The problems come when they are damaged, shorted, overheated, or overcharged. I’m guessing the fire on the plane would have been caused by mishandling the batteries if they are the cause. Any Li-poly of the current generation will have the same problems.

    One of the big issues is that if you charge a li-poly battery that is arranged as cells in series, they do not naturally balance the voltage between the cells. Thus, charging them in series will overcharge some cells while other cells remain undercharged. Any maker that is going to use Li-poly batteries needs to be aware of this issue.

    The chips are anti-competitive nonsense.

  2. The energy density arguement is a rather ridiculous as well. Explosives tend to have midling energy densities compared to many fuels, but can very rapidly convert this energy by very rapid combustion (deflagration/detonation). In the same fashion, it is the capacity of the batteries to discharge (and potentially burn the lithium) very rapidly that makes them dangerous.
    For example the energy density of Coal is roughly 25 MJ/kg as opposed to 4.184 MJ/kg for TNT. Fat comes in at a whopping 38 MJ/kg. Thus if we were simply considering “energy density” as a measure of potential danger, your extra pounds of fat are pound for pound, are fifty times more “dangerous” than the lithium batteries you carry around.
    This also explains the allure of fuel cells, ethanol has an energy density of 29.7 MJ/kg, making it much more efficent (pound for pound) as an energy source than any battery (or TNT for that matter). Although fuel cells have only a ~35% effiency, this still puts them 14 times that of lithium batteries while being as dangerous as a flask of everclear. (lotsa caveats apply at the moment YMMV).

  3. Li is a very interesting atom by itself. The base electronic structure consists of three electrons, and due to shell configuration, the crystalline form is metallic with some interesting spin properties. The problem is, in lithum batteries, due to presence of ions the system is in a quite unstable form. Due to the light nature and fast reaction due to metallic properties I think a big explosion is quite possible when exposed to air under pressure or heat. The reaction rate of Carbon and Fat with air under the same circumstances would be much slower.

    By the way, overcharging lithium reduces the explosive nature, damaging the battery permenantly, But as the resistance increases in the damaged cell, heat becomes the real problem.

  4. Li is a very interesting atom by itself. The base electronic structure consists of three electrons, and due to shell configuration, the crystalline form is metallic with some interesting spin properties. The problem is, in lithum batteries, due to presence of ions the system is in a quite unstable form. Due to the light nature and fast reaction due to metallic properties I think a big explosion is quite possible when exposed to air under pressure or heat. The reaction rate of Carbon and Fat with air under the same circumstances would be much slower.

    By the way, overcharging lithium reduces the explosive nature, damaging the battery permenantly, But as the resistance increases in the damaged cell, heat becomes the real problem.

  5. This area of ‘power source authentication’ is interesting, because it’s surely likely to become even more prevalent, whether that’s for “safety” reasons or simply economic lock-in. Monopole mentions fuel cells – if/when fuel cell cars become common, you can bet they’ll have an advanced authentication syste to force you to use the manufacturer’s own brand of cells. And maybe even hydrogen itself, if that’s possible…

    I’ve blogged about this over at Architectures of Control in Design – any comments very welcome.

  6. I know for a fact that certain big name manufacturers have had issues with counterfeit Lithium Ion rechargable batteries. Considering many camcorders have the batteries mounted at the rear of the camera, next to the user’s face, this can be a serious issue. Many of them are almost impossible to distinguish from the real thing visually. (Click that link for pictures.)

    The only easy way to tell an unsafe counterfeit from an authentic OEM battery is by weight. Not of the battery, silly… of your wallet. Many of the bigger LiIon rechargables will cost anywhere from 30-60 USD for an authentic OEM battery, from a reputable dealer. The counterfeits are usually closer to 10-15 USD and are found at those shady roaming computer shows, shifty looking electronics dealers, and guys standing on street corners that stop you and say “Pssst… wanna buy a battery?”

    OK, so maybe I’m exaggerating that last bit, but you get the idea.

  7. Li ion batteries exploding is complete nonsense. It’s just scare tactics by manufacturers to manipulate the market.

    60 incidents of li ion batteries involving smoke, fire, or explosion…. ya, right. 59 incidents of a tiny puff of smoke, and 1 possible fire/explosion, maybe.

  8. oops… “60 incidents since 1991 that involved batteries catching on fire, smoking or getting hot.” No exposions, even… just “getting hot.”

  9. K27: Yeah, and you didn’t have to listen to a supervisor take a call from a guy who’s video camera detonated in his office, spewing giblets of camcorder and the innards of the battery all over the place. Then there’s the pictures of the Dell laptop going ka-flipping-boom that were all over the net a week or two back. Or all the cell phone batteries from Nokia, Kyocera et al over teh last couple years that may not have detonated, true, but were venting hot gasses that could cause nasty burns. Lithium based batteries really can and really do go boom if provoked.

    The threat from third party cheapo batteries isn’t a fake thing generated by the big electronics manufacturers to make you buy pricey batteries. It isn’t a lie, it’s not an uban myth, and it’s only by the fact that the manufacturers chase down the cretins that make the dangerous knockoff batteries that there haven’t been more accidents.

    Most electronics manufacturers don’t mind the third party accessory manufacturers too much, as long as they don’t put the customers in jeopardy. Energizer, Maxell, Thunderpower and Quantum all make alternative power systems for various products, but since they do their best to make quality products there’s no fallout from the OEMs.

    Get off the conspiracy bandwagon, and get realistic about things. Oh, and please take off the tin foil hat, it just looks silly.

  10. Dinkus, your sensationalized and isolated examples are garbage.

    I have read the info. I have done the research. I have performed the experiments. NOT dangerous.

    They take your fingernail clippers when you board the plane, but you get to keep your laptop. Is that because the nail clipper is way more dangerous?

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