LiPo assembly question
 

I have a 3s pack that wasn't charging, so I took it apart and found a failed solder joint where the 2 tabs overlap. What sort of solder is used to joint these?

Thanks for any help "thumbsup"

If you are lucky, you can use normal electronics solder. Some Lipo cells have tabs that are made from aluminum and I haven't found a way to solder directly on them. There is some special flux you can get but I wasn't able to make it work. Also, sometimes the cells with the aluminum tabs have something like tin bonded to the end of the tab. To me it looks like it was spot welded, but I'm probably wrong. These ones, you can usually make a good connection with solder.

If you are stuck with aluminum tabs, I did find a way to make it work, but let's see how you do first - you might be okay with what you have.

Just crank your iron all the way up and reheat the joint...if its just a cold/bad solder joint

I'm guessing it's aluminum because rosin core solder wouldn't grip at all, even used a liquid flux and it still wouldn't work. I even tried my 450W soldering gun, all it did was make a lot of heat! I'm not a complete novice with electronics, I just don't know diddly about assembling LiPo packs and I'm not ready for another explosion on the work bench.