Stupid. Stupid. Killed a battery but no fire.

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docw009   100 kW

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Stupid. Stupid. Killed a battery but no fire.

Post by docw009 » Jul 22 2019 10:37am

Last night I put a 48V charger by mistake on my 36V 10S-3P shrink wrapped pack. Worse, I had an XT60 adapter plugged into the XT90 discharge port, and thought it was the XT60 charge port. So no BMS protection.

I discovered my error a few hours later when I unplugged the pack, saw it was too warm and saw the wrong charger. Pulled shrink wrap and found most of the cells dead, but one group at 4.3 volts and the pack getting hotter, I put it in a cooler of ice water. It got cold. Added some salt. Tried to go to sleep.

This morning, the cooler was full of black water. I rinsed off the pack, and it started to get warm again. More ice water. Checked the cells. That one group had dissolved the nickel around the + terminals, and two cells were near zero, but the third was still at 4 volts and apparently still self heating. I removed that cell and will deal with it later. I think the other cells can be recycled.

Samsung GA cells, by the way. I'm glad they just died w/o drama while being overcharged. Careless, sloppy, I deserved worse, but I did go thru my usual drill or unplugging the charger before going to bed. Dumb luck. I'll take it.

miro13car   1 MW

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Re: Stupid. Stupid. Killed a battery but no fire.

Post by miro13car » Jul 22 2019 11:18am

High Voltage cut off for individual cell is essential while charging
When any cell reaches whatever max voltage circuit must turn off charger.
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spinningmagnets   100 GW

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Re: Stupid. Stupid. Killed a battery but no fire.

Post by spinningmagnets » Jul 22 2019 11:33am

Thanks for posting this. We all want to shout about our successes, but we often are too embarrassed to confess our mistakes.

Back when I was new to ES, I wanted to test a DIY drive as soon as possible, so I bungee corded a LiPo brick to the cargo rack. OF COURSE that was the one time I hit an unexpected pothole, and didn't realize I had lost the battery for half a block (*I was coasting).

It was easily found, but it was badly dented...

2old   100 kW

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Re: Stupid. Stupid. Killed a battery but no fire.

Post by 2old » Jul 22 2019 12:45pm

Thanks for the cautionary tale. Fortunately for me now, all batteries and charger are 52V except a 36V Haibike Yamaha with a charger that's not compatible (obviously) with any of the batteries.
Last edited by 2old on Jul 23 2019 8:23am, edited 1 time in total.

john61ct   100 kW

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Re: Stupid. Stupid. Killed a battery but no fire.

Post by john61ct » Jul 22 2019 1:38pm

Yes it seems a sensible precaution would be standardizing on different physical connections for different voltages.

HVC independent of the chargers of course even better, but both best of all.

miro13car   1 MW

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Re: Stupid. Stupid. Killed a battery but no fire.

Post by miro13car » Jul 22 2019 1:50pm

I do not use BMS on my 11S2P pack
I use open collector alarm output of CELLLOG monitor . This output can be cofigured as NC or NO.
I use this NC to connect colis of 2 relays in series
contacts of these 2 relays carry 120V to charger.
once any cell reaches 4.03V alarm output changes from NC to open.
It is pity such a beautiful monitor is discontinued and when available it cost crazy 72 dollarsUS
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MadRhino   100 GW

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Re: Stupid. Stupid. Killed a battery but no fire.

Post by MadRhino » Jul 22 2019 5:41pm

I just scrapped 4 lipo bricks for a bullet unplugged. I did ride full power on half capacity, until the smell warning. 4 bricks double size puffed, good for the pal of water and de-icing salt.

Like they say: Sh*t happens
Sunny tomorrow
Make it fool-proof, and I will make a better fool.
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flat tire   1 MW

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Re: Stupid. Stupid. Killed a battery but no fire.

Post by flat tire » Jul 22 2019 6:25pm

Gunfire is more fun than salt water.

--Hunter S Thompson

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Drunkskunk   100 GW

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Re: Stupid. Stupid. Killed a battery but no fire.

Post by Drunkskunk » Jul 22 2019 7:10pm

Thanks for posting. That realy sucks.

After Richard Hamond crashed the Rimac Concept One, they had cells self heating to ignition for days after the fire was put out. As common as batteries are, it's easy to forget how dangerous they can be. Any questionable cells I have end up on the BBQ or in the fire barrel. I haven't had to turn any into home-made Lithium icecream yet.
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LeftieBiker   10 kW

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Re: Stupid. Stupid. Killed a battery but no fire.

Post by LeftieBiker » Jul 22 2019 7:17pm

Wasn't water a bad idea unless the pack was in a sealed, heavy bag?

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Drunkskunk   100 GW

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Re: Stupid. Stupid. Killed a battery but no fire.

Post by Drunkskunk » Jul 22 2019 8:47pm

LeftieBiker wrote:
Jul 22 2019 7:17pm
Wasn't water a bad idea unless the pack was in a sealed, heavy bag?
Nope. Kills the flame, cools the cells in thermal run-away, and with the addition of salt, produces a way to discharge the cells to make them safe for disposal.

The danger from the lithium hitting the water doesn't really exist. the lithium is already combined with other elements. Sodium explodes in water, but combined with Chlorine to make table salt, is totally safe to throw in water. Same thing with Lithium. And the amount in a battery is minuscule. A 100 watt battery may have 5 to 10 grams of lithium.
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