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0 I recently saw a post in my local group that someone had a LiPo fire. I am a bit worried because I store all my batteries in the house and no where else to put them . I am wondering what can cause LiPo to set on fire and explode?
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388 Lipo are pretty volatile.
Things that can cause fire:
Unseen damage after crash.
Small puncture not being notice and lipo gets exposed to air.
Improper charging. Like overcharging.
Poor made packs
Not retiring old packs that are puffy
A short
Storage too hot.
High voltage storage instead of storage voltage.
I keep all my lipos at home in an ammo container.
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45 I've only had one fire but it was a scary one. They always say never leave a lipo unattended when it's on the charger, but I guess after years with no problems I got a little complacent. Anyhow, I was upstairs when I smelled something. I had a bunch lipos all in one place on my workbench and there were about 10 of them in full flame. I managed to put it out but was very close to calling 911. Anyhow to get to the point, the first lipo that caused it actually went off from over discharging. I'm MUCH more careful now
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0 There are several common causes of LiPo battery failure and fires.
1. External short circuit
Due to the extremely low internal resistance of the battery large currents will flow when there's a short-circuit across the positive and negative terminal. According to Ohm's law (R=V/I, hence P=V*I or P=V^2*R or P=I^2*R) this will result in excessive heat production in the LiPo cells, causing a thermal runaway and for the cells to explosively outgass.
2. Extreme discharge
This is very similar to an external short-circuit, the power draw from the LiPo battery is excessive and leads to tremendous heat production in the cells which causes for a thermal runaway and the cells to physically blow up and outgass explosively.
3. Internal short-circuit
This is a failure mode that's hard to diagnose, but can be both a manufacturing defect where the insulating layer between the anode and cathode of a cell has thinned to a point that the cell short-circuits internally, or a mechanical defect from abusing the cell physically with the same cause. Heat buildup and thermal runaway again will quickly and violently destroy the cell.
this can actually happen with a slow self-discharge resulting in one cell getting warm but not so hot it explodes, so if you ever damage a pack and one bit of it feels suspiciously warm some time after the flight it's a good idea to monitor it. More often than not the next day one cell will be zero volts.
4. Over-charge
If a cell is charged beyond capacity excess heat is generated, as the cell cannot absorb more energy hence the excess energy is dissipated away as heat, causing for the cell to, again, suffer from heat buildup, thermal runaway and subsequently explosive outgassing.
5. Over-discharge
If a cell is discharged below the minimum voltage (typically 3.0V) this causes thinning of the electrode layers and could locally result in spots that are thinner than others, causing for an internal short-circuit when the cell is charged again. Heat buildup will then quickly result in thermal runaway and catastrophic failure.
Conclusion
As you probably noticed, the eventual reason for LiPo batteries to burst in flame is heat.
The chemistry of a LiPo battery does not tolerate overheating as the cathode will start to release oxygen into the electrolyte. This released oxygen subsequently has an exothermal (heat generating) reaction with the graphite anode that's plated with lithium and thermal runaway creates an avalanche effect which will cause the cell to burst into flames.
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78 Like VooDoo I store and transport in ammo cans that are fire board lined and have some holes to vent pressure. I charge on oven broiler pans. I do leave them unattended while charging and I shouldn't. Never had a problem in 11 years...hope it continues
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16 Ammo can for me. And I charge/discharge on a piece of leftover red slate stepping stone.
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2 I had a tiny whoop 1S battery catch on fire the other day. The little plastic shroud where the connector mounts was loose (its actually loose on all of the PulseRC ones, crappy) and pulled off enough that the two leads inside shorted. It spit fire out like a little 2" afterburner. Luckily it was near my metal keyboard tray so i threw it on that, ran and got some tongs, and then threw it outside on the driveway. It lasted what seems like maybe 10seconds. To make sure it was dead i twisted the leads together and put it in a bowl of salt water for awhile.
I definitely store my batteries in a lipo bag and charge them while i'm around on a metal keyboard tray.
Speaking of which, i always feel a little nervous throwing all my batteries in the lipo bag. There's a slim chance that something in there could make contact and short/arc/burn. Do you guys cover your connectors or anything when you have a bunch in a box/bag?
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0 over discharge, short circuit, large voltage differences among cells, Puncture, fall can cause the fire in the lipo, and over these factors , the over discharge is the most important one, which cover the 80% of lipo fire.
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