Dry Cell Batteries
by Marlin
(Deer Park, WA)
Odyssey Dry Cell Batteries
Is there a better alternative to dry cell batteries or lead acid batteries available for electric cars?
I've heard that lithium batteries were explosive, is this true?
Hi, Marlin -
When electric car people say "dry cell batteries", they're usually either talking about the gel lead acid or the AGM lead acid golf cart batteries you can get from any golf cart or marine battery supplier. You don't have to put water in these, different from the "flooded" or "wet" lead acid battery.
There are other dry cell batteries, though, that are used in electric vehicles and that are better (and more expensive) than the lead acid dry cell batteries.
- NiCd Dry cell batteries, like the ones you see in these light EVs at the EV Photo Album;
- Graphite foam lead acid batteries, namely the Firefly battery, which is the next step in lead acid battery technology, but not quite available yet;
- NiMH batteries, which are not available in large format, thanks to Chevron/Cobasys owning the patents and taking them off the market, but are available in smaller packages which some are configuring for use in EVs;
- More obscure dry cell battery chemistries (found only in Europe, used experimentally by colleges, or prohibitively expensive);
- Lithium chemistries like Lithium ion, Lithium polymer (LiPo) and Lithium Iron Phosphate (LiFePO4).
Which leads us to your next question: Will lithium batteries explode? The answer is no. That's sort of been overplayed by the media...shocking, I know; )
What a lithium battery WILL do is catch fire when it's defective or punctured or overheated or overcharged, in a runaway chemical reaction known as "thermal runaway".
This means the chemical reaction that makes the battery do its thing starts to run out of control, and then the heat this out-of-control reaction generates also causes the cells around it to start running out of control. You might have seen some YouTube footage of a laptop battery on a barbecue grill, which demonstrates this perfectly.
Several types of lithium batteries have been developed lately which are designed to resist this tendency to "thermal runaway"; the two most widely used in EVs are Lithium polymer (LiPo) and Lithium Iron Phosphate (LiFePO4).
Regards,
Lynne
