Battery problem **

Hello everyone, I opened my board hoping to install a Bluetooth module to he vesc. Instead I opened it only to find that my battery was emitting smoke. I quickly ripped the connections off as to prevent a fire or explosion. The orange wire from the BMS was completed burnt as well. I’m not sure why this happened but when I desoldered the pack and re Soldered it I kept getting sparks from one battery port ( The one with the purple wire). (I know the negative nickel strip is off I’ve reattached it since)Can anyone answer why this is? I would really appreciate it15342080887467376134023808635031153420815818184064492213888950231534208230355704953248080066741

Take it outdoors IMMEDIATELY until you know why it’s venting. Like RIGHT NOW.


Take @b264’s advice immediately.

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It’s very likely that the problem was caused when it was opened up because if it was smoking, by no means would it be smoking for days and still be operational and not a fireball

Already put it out, sitting on a large cement area so won’t catch anything on fire if something happens

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Do you have a multimeter? Are you able to check the voltage of each P-pack

Yea, I’ll do that right now

Also I’d unplug the BMS too until you know what’s wrong

Who made this pack?!

I did about 1 month ago

Disconnect the bms and check the voltage of each p group as mentioned above.

Did you spot weld or solder the nickel strips onto the pack?

The series connections look under built. Esp considering I’m guessing that’s nickel plated steel as I’ve never seen true 100% nickel sold in that format. And I looked for a long fricken time.

I inserted each cell into a 18650 holder and soldered onto it to avoid heating batteries.

Should I double it up?

Get rid of the battery holder’s they aren’t designed to handle the currents or vibrations. All that being said taking a closer look at your pictures it looks like on your bms the bottom most mosfet is fried the pins look a little scorched and I’m guessing something shorted when you where taking off the enclosure.

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The heat will travel from the nickel onto the cell unless you’re soldering before attaching to the cell.

Regardless, get yourself a spot welder, they’re not terribly expensive and you’ll save yourself a lot of headache. Don’t solder directly onto the cell. And yes, get rid of those cell holders.

Okay, I have a new BMS already on its was to replace that one. Going to get rid of those holders and get myself a spot welder. Any you prefer?

Is there a spot welder that you prefer or found works well

The “boss” … Easy to use amd smaller than a sunko which has its own issues and requirements

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Do you have a link?