Battries and soldering


Active Member
Dec 16, 2016
So I have a handheld vac that has internal rechargeable batteries and charging stand and it won't hold a charge anymore. I opened it up easy and it has several sets of unbranded rechargeable AA batteries where two batteries are in parallel with some soldering between their ends with a small rectangular piece of metal soldered to each and then wires going to next set in series.

I don't have much experience with this but feel like it would be an easy project to improve my skills and include my kids on.

Can someone more knowledgeable confirm this should be an easy project and maybe recommend which inexpensive soldering iron, solder, etc... I should use and any tips you might have. Am I going to blow up the batteries or something with the heat from soldering iron if not careful and need face mask or something? Ha. I was planning to just buy random AA rechargeables. I think the current ones are only 1400mah so the new ones could be higher and increase runtime too....



Active Member
Mar 10, 2016
Those tabs are usually spot welded. Solder often doesn't stick well to standard battery ends due to the metal they plate them with. If you buy the batteries with the tabs pre welded, you can solder the tabs without too much hassle.

Hobbyking sells a decent temp controlled soldering iron for about $20. It takes Hakko tips, but the one that it comes with is fine for what you are doing. Kester no-clean lead based solder is the gold standard for quality and ease of use. If you are new to soldering, avoid the lead-free stuff. It is much harder to get a good joint with.