LiPo Fire Information

[Alan B]

Testing a tiny RC pack in a huge steel box is not very representative of what would happen in a larger lithium battery fire.

The steel box could even convert a fireball into a much more explosive event with shrapnel.

 

[fechter]

Testing a tiny RC pack in a huge steel box is not very representative of what would happen in a larger lithium battery fire.
The steel box could even convert a fireball into a much more explosive event with shrapnel.

My experience is the Lipo fires are largely due to the solvent. A steel box would do a good job of confining the vapor and preventing spread of fire.
The box should have a vent or some mechanism to prevent pressure build-up, but the 'explosion' from a 10Ahr pouch is more like the pouch popping and the vapor igniting. Without a supply of oxygen, the cell will smoke and give off solvent vapor, but not burn.

But that is with a little 10Ahr cell. I think we need a larger scale test ES version of Mythbusters.

 

[Alan B]

My understanding is that the chemistry provides the oxygen, the fuel and the ignition temperature in many cases so it may not be necessary for outside oxygen at all.

18650's are already contained in small volume cans, and they have burned.

We've seen Headways burn nicely, they are in cans.

A quick search turns up no Nissan Leaf fires, which is quite a good track record, perhaps their cans do help. They have a rather extensive packaging arrangement for their cells that significantly reduces the chances of mechanical damage to the pouches inside.

It takes a complete system design to safeguard high energy batteries. No one component is sufficient. Preventing mechanical damage, shorts, keeping them in a safe thermal temperature range, preventing overdischarging and overcharging is ALL required for battery safety.

 

[fechter]

Yes, I think they can self-ignite under some conditions. It does make an impressive fuel-oxygen explosion right at first, but the oxygen produced by the battery is minimal and in an enclosure would not be enough to sustain a flame. Any enclosure needs to have some provision to vent.

 

[Boyntonstu]

Yes, I think they can self-ignite under some conditions. It does make an impressive fuel-oxygen explosion right at first, but the oxygen produced by the battery is minimal and in an enclosure would not be enough to sustain a flame. Any enclosure needs to have some provision to vent.

Would a vent allow oxygen and make the fire spread?

What about a check valve pressure relief vent like on a hot water heater?

 

[spdas]

Although I am a Nooby with Lipo, I know now that charging and discharging properly is key. I am off-grid on solar here and now use an Outback charge controller that precisely-gently charges the batteries.
I only charge to 4.12V and never go below 55v. (with 16s). I am not using BMS, but every week I check the individual voltage with a cellog and if needed use a balance board to equalize the cells.
I am now hooking up a Half-pack voltage LED's so I can see any cells possibly getting weak.
francis

 

[Eskimo]

Eleven years now almost daily use without any problems.
Shorted, crashed, abused, run em totally empty. Your average cat is more dangerous.
Of course you have to know what you are doing with them. They are not for the noobs who think that customer of a product is responsibility-free always.
I always balance-charge them to 4.20. 4.30 is my record, charger was faulty then.
Some Turnigy chargers are faulty. Calibrated badly or otherwise faulty, readings are not correct.
Batteries are not the danger number one, chargers are.
It"s just biased attitude basically. My country has a small population, but still we have around 500 car fires every year according to insurance statistics. Maybe five battery fires including cell phones.
Uncredible media coverage if one battery burns down. When a gasoline car burns down, nothing. Business as usual.

 

[motomech]

Your average cat is more dangerous :lol:

Apparently Lipo bricks make a convenient head-bashing clubs for Elitists to exercise more control on how and where us simpletons can use it.
No doubt more Government control is needed

 

[Boyntonstu]

Your average cat is more dangerous :lol:

Apparently Lipo bricks make a convenient head-bashing clubs for Elitists to exercise more control on how and where us simpletons can use it.
No doubt more Government control is needed

No doubt no more Government control is needed, however judging from some of the fireball stories, there are a bunch of simpletons out there playing with LiPo matches.

 

[Boyntonstu]

FWIW

My friend loads trailers at a Walmart distribution center in Rolla, MO.

He has handled and thrown many boxes marked Lithium Batteries.

Some of them were the Everstart Boosters.

He was the one who told me about them.

He has never seen a LiPo fire.

 

[Alan B]

Most of us use and like Lipos. We don't want them to be banned or blamed for fires. But they are quite flammable, and they do burn from time to time even with the best of systems. Recent experiences with hoverboards show that mistakes can result in a very high failure rate. But the failures are not limited to low cost and poorly manufactured imported toys. The failure rate is better, but even the good stuff has problems occasionally:

http://www.economist.com/blogs/economist-explains/2014/01/economist-explains-19

These fires are not common, but when they occur the results can be devastating.

Take care and be prepared.

 

[spdas]

Putting things in perspective:

I would much rather stand beside a lipo and overcharge it and have it "Roman Candle", than light a match into a gas tank when refueling.

Point is the danger is only because of lack of education... (we know not to light a match while refueling) but we sometimes are bewildered that a Lipo will enflame when we use it stupidly.

francis