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Comment by whatshisface | Hacker News Reader

This is not so much a Tesla hardware issue as it is a lithium ion issue. Tesla's packs are not more or less dangerous than other lithium ion battery packs.

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This is not true. There are different chemistries. Tesla hardware, as many others, requires an active cooling system because of the KNOWN thermal issues with involving cobalt. There are lithium ion batteries without cobalt, such as Simpliphi, that do not have any runaway heat issues and therefore do not require a any cooling system, but this lithium chemistry increases the cost.

Active cooling in lithium (or any chemistry) batteries exists to allow fast charging and discharging of the battery, as those actions produce heat. Without any cooling system, you're limited by the passive heat dissipation of the battery, which largely depends on the internal resistance. You can lower the internal resistance at the expensive of some other properties (mostly efficiency).

If you don't believe this is a problem in any battery chemistry, I challenge you to find a battery that does not heat up while being charged (they all do, due to thermodynamic inefficiencies). Thermal runaway in Lithium-ion specifically is largely an effect of the lithium decomposing as a result of large heat input (by a short or physical damage). Once this has occured the battery will go through several stages of burning.

The runaway heat issues, with the chemistries applied now, are mainly due to which other elements are involved. Cobalt is a huge factor.

It is true all batteries heat when charging, but this is not what I am talking about here. Simpliphi batteries do not require any cooling system because the chemistry is more thermally stable and does not have a risk of thermal runaway, even charging at high power. Tesla batteries have a cooling system not for the heat generated by charging alone, but because of the runaway thermal reactions involving cobalt.

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