I just want to be sure I did the right thing. I popped an internal connection on one of my hardcase lipos recently. Given that it is a very new battery in my collection, I though I’d try to fix it..

After spending about an hour getting the case open, I started checking connections and peeling off layers of kapton tape, I finally found the broken connection. It looked repairable, so I went for it.

I first tried liquid flux and regular solder, but could get the connection to stick, even when holding it together while it cooled. Next, i used a little solder paste heated the joint quickly and all seemed well. Voltage from both cells and everything!

Is solder paste good enough long term? Any known resistance issues? Breakage?

thanks!

Thanks for the replies so far. The battery hasn’t done anything weird yet, but I’ll give it a stress test tomorrow. Better at the track than on my bench. I think that joint might still be a weak spot. A few laps in my buggy will give it a good rattling. There is regular solder in the joint, but it took tw solder paste to wake it up.

Aluminum solder? You lost me. I’m just using old reliable 60/40. (Tin/lead)

i’m thinking a spot welder for assembling metal tabs on plastic lipo cells might be kind of a specialty item.

thanks again!

Cool. Thanks.

I just stumbled across some aluminum/flux solder paste locally that’s designed for all gauges and has a low melting point. Battery safe!

I didn’t get a chance to punish the battery yesterday - I’m sick as a dog. Food poisoning FTW!