John in CR
100 TW
The problem with the RC lipo is the chemistry, because it so easily goes into thermal runaway.
Arkz said:Everyone saying compression is the answer, surely if they try to swell under compression they will burst open and vent. Or worse due to being pressed together, should one set fire it's gonna pass straight to the next cells.
Sunder said:John in CR is correct in saying that RC LiPo's chemistry goes too easily into thermal runaway... But moving to 18650 or other cylindrical cell doesn't solve that issue. There's at least 5 different types of Lithium Ion chemistries that go into 18650, and one of them is LiCo - the same "dangerous" anode that goes into RC LiPo. That doesn't mean the electrolyte is the same though - the solid polymer burns better, but that certainly doesn't preclude a fire from starting in LiCo based 18650s. E.g. the ICR named cells.
18650 is just a format, it says nothing about the volatility of the contents.
flippy said:technically you are correct but you are baltingly ignoring a few facts while mentioning them yourself.
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Alan B said:Pouches require compression, it is a battery packaging necessity. One of the reasons it is hard to buy commercial pouches is they don't trust random customers to properly constrain them, so they only sell the high end units to verified clients.
but it doesnt. they dont last long, tend to blow up when actually loaded to their ratings and have systemic puffing issues. all off those things do not apply to properly compressed pouches like the ones you find in cars or just 18650 cells.Alan B said:The RC lipo packaging seems to meet the compression requirements just fine.
Actually, the results of millions of RC packs sold suggest that compression beyond standard shrinkwrap, is not essential.flippy said:but it doesnt. they dont last long, tend to blow up when actually loaded to their ratings and have systemic puffing issues. all off those things do not apply to properly compressed pouches like the ones you find in cars or just 18650 cells.Alan B said:The RC lipo packaging seems to meet the compression requirements just fine.
jonescg said:You guys speak of pouch cells as if expansion is normal - it's not! If a pouch cell is puffing it's because something has gone wrong - either an internal short, physical trauma, over charge or over discharge, or the cells were allowed to get too hot for too long.