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points by klaff 1 day ago | 0 comments
The energy released during a fire is higher than what is accessible by discharging the battery. Here's one paper describing ratios from 1.25 to 5 depending on access to oxygen during the combustion.

https://cea.hal.science/cea-05234204v1/document

[–] ggreer 1 day ago
I'm pretty sure you're reading the paper wrong. Of the 29 tests they did, 5 were in air, and all of those were with fully charged batteries. The 5x ratio is the difference between electrical energy stored in the battery and energy released in atmosphere. They did not measure different states of charge versus energy released in atmosphere. That's why the figures for the nitrogen and atmosphere tests are bar charts instead of line charts.

The relationship between energy stored and energy released was mostly determined by how big the batteries were, not their state of charge. Only 4 of their tests varied state of charge, and those were all in vacuum (with cells #1 & #6), and state of charge was never below 60%.

[–] klaff 1 day ago
I wasn't clear, sorry, and you understood the point from the article. I thought you might have been assuming that a 100 kWh battery would produce 100 kWh of energy when burned, and I was trying to point out that when the battery is burned, you can get a much larger amount of energy. My apologies for wasting your time.