In my first instructable I needed to use an AA Battery to plate some copper onto a quarter, and I ran into an issue. I didn't have a battery holder, and I was too cheap to go out and buy one. So I scoured the internet looking for ways to solder a wire directly onto a battery and found nothing except that a tin strip could be welded onto a battery.
Like most people I don't have a welder so I started experimenting with using flux and other various agents until i finally found that filing the end of the battery would allow solder to pool. then I could solder a wire onto it easily.
This technique can be used for both normal and rechargeable batteries, so if you need to replace some rechargeable batteries in battery packs like the one from the Xbox 360 you can now do it. I also used it when making this instructable https://www.instructables.com/id/Copper-plating-made-easy/.
Comments are welcome and appreciated
Step 1: Materials
What ya need der:
-A Soldering iron
-Some rosin core solder
-Two pieces of wire preferably red and black to avoid confusion
-Wire Strippers(not shown, but still needed)
-Some Skill with Soldering
Step 2: Filing the Terminals
Take a file to the positive and negative ends of the battery and rough them up. make sure the whole surface of the battery terminal is evenly rough. its OK if you mess up the covering a little bit.
Step 3: Applying the Solder
Make sure your soldering iron is clean and then tin the tip of it. Secure the battery in a vice or clamp or something and make sure your iron is hot and ready. Using the iron heat up the terminal of the battery and apply solder, you don't have to heat the battery terminal all the way up to solder melting temperature, you can just use the iron to melt the solder. The solder should pool on the terminal, if it doesnt you need to rough it up more, and try again.
Step 4: Attaching the Wires
Strip both ends of each wire and then tin one end of each wire. Use the iron to heat up the solder on the terminal and insert the tinned end of the wire into the solder pool. FYI red wire is positive, black wire is for negative, common, or ground. and thats it. It may not be the simplest way of utilizing a battery, but you cant get much cheaper.