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SpiritDCRed t1_iuev8eh wrote

Reply to comment by hblok in Fires from exploding e-bike batteries multiply in NYC — sometimes fatally by zsreport

Biggest way to avoid this is to never let lithium RC batteries charge unattended and use quality chargers. I’ve also seen lots of hobbyists build little isolation chambers out of ammo cans and such, so if it catches on fire it is enclosed.

Edit: this thread has some good replies

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Envect t1_iuf58gj wrote

Don't higher quality chargers have protections built in? I used to play airsoft and I swear my charger had some safety shut off. I still kept a close eye on it though.

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thisplacemakesmeangr t1_iufwhpd wrote

They say the problem generally comes when they don't use stock chargers.

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asdaaaaaaaa t1_iug4a83 wrote

That's my understanding as well. Modifications or people getting really cheap stuff that's not directly meant for the batteries/device.

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WesBur13 t1_iugqoa3 wrote

Ehh I argues to say most aftermarket chargers have much better control and quality compared to included chargers. I personally use ISDT and HiTech brand chargers and they are leaps and bounds beyond what is included with air soft and RC related stuff.

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gonewild9676 t1_iuhb2gm wrote

Those are probably ok. The likely issue is that they go on Amazon and see good chargers for $150 and other chargers for $20 and they are $20 for a reason.

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notFREEfood t1_iufk5sd wrote

I've got a name-brand ebike, and from what I can tell, the charger automatically shuts off once the battery is fully charged.

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[deleted] t1_iuflzm3 wrote

[deleted]

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rpkarma t1_iug55wy wrote

It’s one of the most common though: people using cheap third party chargers without good protection circuits/overcharge protection.

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Zinrockin t1_iugl9xk wrote

Yeah if you’re not buying a charger with a long list of protections then you’re gambling.

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doommaster t1_iug236y wrote

You need a good BMS too, the issues mostly arises from cells being overcharged because single cells are broken and not taking a charge anymore.
With NiCad and NiMH cells the batteries would just get warm and eventually the charger would hit a time or temperature limit.
With Lithium cells the charger or BMS have to detect this condition and stop the charge.
Most lithium cells will start breaking down very quickly once they are being overcharged, which is often resulting in fires.
On the other hand, fires of cars and such are also not really uncommon but often happen outside and cars also do not scale well in high density areas but eBikes eventually will.
What worsens the whole situation is the inconsequential regulation or the lack there of, of eBikes which prevents bigger players from entering the market and creating a common quality level.
Looking at Europe and Japan far over 90% of the eBikes are big brands which could never tolerate such failures in their product lines.

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robotobo t1_iuiv5ca wrote

Are people actually charging these batteries without looking at each cell group? As somebody who works with lithium batteries, that's terrifying.

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doommaster t1_iujttg7 wrote

People are dumb, and sellers/manufacturers cut corners all the time.

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DancesWithBadgers t1_iuhfk0m wrote

It's all money. A good charger will have protection; but there's also extra protection in the device itself for balancing the cells. All of these things cost extra to manufacture.

There's also things that no amount of electronic protection can save you from...like water; physical damage of a cell; or just a badly-manufactured cell. Lithium cells are prone to thermal runaway which is scientese for saying they're really, really bad at dealing with short-circuits.

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weizXR t1_iuf660d wrote

100%: You need a proper charger, one that monitors the charge and knows when to stop.

And yea, this obviously doesn't apply to just bikes, it applies to all of those types of batteries.

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Masterjts t1_iuhtd1u wrote

That is how I charge and store mine, in a metal ammo can. Lost several batteries to charging fires and two to storage fires over the years. Never did more than destroy everything in the can though.

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ILoveThisPlace t1_iug1zvq wrote

This is good advice. Also do not store too cold or too hot. Although that would mean storing the battery inside in a basement or something where fire can be bad. So next thing you can do that I've been debating is purchasing a fireproof cabinet and placing it on a cement wall with a food of space from anything flammable. I'd store all my Lithium batteries there probably... power tools, lawn equipment battery, cab booster, ebike battery.

Buying an ebike off a trusted known brand will lead to better luck. A tried a true cell from.... crap I was once told the 3 big trustworthy battery companies... i think it was Samsung, LG, and I can't remember the third, maybe Phillips... bah, anyway, those cheap Chinese batteries from aliexpress should be avoided. They have not done the northamerican safety tests for batteries. You can not trust them. It's unlikely an ebike company will build there own battery. They would get it sourced and it would be up to the company designing the bike to do their due diligence.

So it would be good to research your ebike or the battery vendor and see if you can find some info on defective batteries.

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shaggy99 t1_iug427e wrote

Going back about 35 years or so, guys racing RC buggies would waterproof their batteries and charge them in a bucket of cold water. I think they were something other than Lithium though. metal hydride?

I remember one guy got called for his race, he grabbed a pack from the bucket and disconnected it, looked at it for a second and threw it back in the bucket and shook his hand. "I'll use the spare"

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WesBur13 t1_iugqujt wrote

NIHM and NiCD batteries used to be charged at high current on timer chargers. That practice has fallen away with lithium packs that you usually charge at 1-2C. Chargers of the same price range nowadays have better logic than a dial timer.

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