Hey guys, i recently purchased a water damaged raldey, and the bms is unfortunately shot, the board has a 50.4v charger, Battery is rated at 44V and bms is 12s4p w/ 40a ground, im not sure if I can just bypass and charge it. BOARD IS RALDEY WASP. If anyone can help me find a good bms for it itd be greatly appreciated, I just want a quick long lasting repair, board is fine otherwise
no
the battery is water damaged
bring the battery to a recycling center
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It’s a fire hazard to do that just a heads up the whole battery could be compromised I reccomend you get a new pack built
1: get rid of that battery
12S nominal is ~44.4V, that’s not full charge voltage, whivh is 50.4
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Insert assess the damage joke here
I mean it works still though, I tested all leads to the battery, and i checked all cells and they look brand new. I dont think the battery is toast, except for the fact cell 12 reads the same as cell 11, im not sure if thats normal
I checked the pack personally, the battery setup was relatively waterproofed, It doesnt look compromised in the slightest. Battery hasnt been charged in about 2 months.
aka, id rather rebuilt the toasted portion of the battery myself if needed, but i kinda have my doubts
battery was dead when board took a dump, the leads on the bms (12pin) looked a little shot on the bms side (since its in a sperate chamber) so im pretty sure the bms took a dookie, when I did a bypass it power up, and works. But battery is low voltage atm. & Cell 12 reads the same as cell 11, but cell 12 reads what total battery voltage is on multimeter.
It sounds like you’re trying to say rhat cell 12 is at exactly 0 volts… in which case the battery is fucked.
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well cell 11 was about 44v, but so was cell 12, would that mean cell 12 is toast? Voltage from battery is the same as cell 12 & 11 (44v) I doublt ill have to trash the whole pack, it looks relatively repairable since they did a shit job parts wise
Without trying to sound rude, you have absolutely no idea what you’re dealing with.
Please make the pack safe by insulating any conductive parts and take it to a local recycling center that accepts lithium batteries.
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just toss it properly, it’s a fire hazard and not worth the effort of repair
I get you just want me to be safe, but I have a relatively large property and am willing to a little take risk, I only work on it outside, so id like to do some final test to see if it really is toast. What makes you think the battery is compromised? Theres no signs of anything being wrong with it? Its located in its own waterproof compartment? Worst case ill have to just order a new pack, but id still like to understand & troubleshoot.
the bms was definitely shot on the board, it was reading 30v from its connection. or was that a safety? I get im a absolute beginner, but ive dabbled in building batteries for other projects, this pack looks diy asf
You’re not the first person who’s asked for guidance on battery repair and you won’t be the last.
Most experienced battery builders will tell you the same thing…
If it needs to be repaired, its not worth repairing.
you already tested it
it’s toast
and it’s water damaged, so the chances of other cells being done is high. so no, it’s not worth it, even to your large proptery
You will never get that battery pack to work reliably, here’s why:
Cell 12 is at 0V, if you charge it back up there’s a good chance that it will just ignite. Even if it won’t, the battery pack will never be safe to use, and even if you try and it will work somewhat purely because of luck, it’s going to have less capacity then the others and a higher internal resistance, so it’s voltage will drift away, which is not good. Most battery cell manufacturers tell you that you have to throw away a cell if it gets below 2.5V, even for just a short period. Yours is at 0V and probably it’s been sitting there for a good while. Even if you are super lucky and manage to revive it and think it’s working well. There will be an unignorable chance that during one time you are charging it, it will catch on fire, as this cell group is seriously damaged chemically. Trust me, you don’t want to handle liion battery fires. There’s no way to put them out, and they produce a lot of very toxic gases.
Also, replacing only the dead group of cells is not a viable option, because you should never mix new cells and old cells in a battery pack. The voltages will drift away over time due to the different capacities and internal resistances, and if you have an unbalanced pack, it’s very easy to completely ruin it by overcharging or overdischarging certain cells in the pack. You have to replace all cells, which means a completely new battery pack.
Also, multiple people including myself have commented here who are very experienced battery builders. Please take their advice, just insulate all conductive points on the battery, and take it to a recycling center.
The risk is not little. It’s very high risk for little to no reward. Liion batteries should be taken really seriously.
Don’t listen to them. They’re haters. U can make this work u just gotta dig deep. Goonies never die, this battery deserved to live a life & it’s now your responsibility to see that through.
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This is funny, but not your finest moment as a community member.
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