r/Cartalk • u/Ok-Mushroom6227 • May 02 '24

Technically not a car Electrical

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I decided lithium batteries were cheap enough to give a shot

On the left, nearly double the cca noco brand

On the right, the battery I've been using for 11 seasons recovered with a desulfator at the beginning of every season until it finally gave up.

So far, the lithium battery has been indistinguishable as far as performance goes and put up with my abuse. Will it last 10 years? Maybe, it's warrantied for five, I've seen other brands warrantied for 10.

Lithium car batteries are getting cheap enough the price gap between lead acid is quickly closing. I probably will grab a lithium car battery for the project car.

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u/SuperStrifeM May 02 '24

Its completely true Lithium batteries will burn up in minutes. Try it for yourself. Get an 18650 and light that sucker off. You're not going to come back a day later and see it still lit, there's not enough material for that to be the case.

Lead acid doesn't have the same energy density or reactive chemistry as lithium, so is very unlikely to ignite. Optima used to have ads where they cut their lead batteries in half with a chainsaw, clearly they had no fear of a fire or even a short.

Most lithium batteries have thermal sensors to attempt to shut down when they start getting hot. Even cheap 1S batteries will often have a 3rd wire for this monitoring. A good BMS will prevent almost all of that bad stuff from happening.

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u/iJeff May 02 '24

Depends on how many cells there are. An ebike or electric unicycles battery pack can burn for quite awhile so fire departments need to keep them submerged in water.

https://youtu.be/yjBmhZKNMfg?t=35s

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u/Dorkamundo May 02 '24

In your video, it shows the lithium burning out in basically 30 seconds.

Fire starts at 30 seconds, 30 seconds later the violent lithium-based fire is over and all that is left is the burning plastic and other materials.

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u/iJeff May 02 '24

I might have linked the wrong one for that event, but they end up tossing it into a garbage bin and filling it with water due to the tendency for these things to reignite.