ET#32. Can I fix a Vax OnePwr Battery with a replacement BMS from AliExpress?

A brief attempt to fix a faulty Vax OnePwr battery.

[@andrewrichardson8672]

Good to find these two videos about this battery. I had bought a pattern battery and before even trying this replacement I went to "jump" the old battery by connecting negative to negative and positive to positive in the hope that the little extra voltage would was all that was needed to get the battery charging, being hopefully above the threshold for the requirements of the charger. I screwed up and connected negatives to positives and fried the brand new battery. So much for me saving and repairing, I ruined one. I have seen new boards for sale from eBay. Do you think that maybe replacing the blown resistor on your battery BMS would have fixed the fault or is a known fault code response? Many thanks and keep trying.

[@ECEtek]

Ouch, an expensive mistake there mate! Easy to do though. Might be worth stripping the batteries to see what the issues were. Make a video and let me know when you post it - I'll watch it to see what went on. You might be able to make a good one from the two - or at least salvage the LiPos. Unfortunately I didn't know the history of the battery I had - so I don't really know what caused the resistor to blow in the first place. We can assume it was a pretty big current surge that would cause that amount of damage. Unless it was possible to identify what went wrong it would be hit and miss on whether replacing the damaged component would fix it. If the underlying root cause was unknown, it could just blow again in exactly the same way - or it might work fine. I could have opened up the good battery and hoped that the same BMS had been used and so identify the correct component for replacement purposes. We don't know what other issues may have been caused. The blown component may have acted like a fuse and saved everything further downstream - or not. My need for a spare wasn't urgent, so, for me, not worth the effort or time to replace it (and the tracks etc that had also gone). Thanks for your interest and time taken to comment!