RC How To:
Change Battery Connectors Safely - 2
Once the tinning is done for the connectors, it's now time for the battery. Here is the most important step. ONLY CUT ONE WIRE AT A TIME. I usually start with the positive wire, but it doesn't matter which is first, only that one at a time is done.
This ensures that you don't accidentally touch the positive and negative wires together. Bad things can happen if that occurs. By cutting one at a time you keep the other wire shielded while the other is exposed.
Using the other side of the jig, I tin the battery wires. These are 10 gauge, so it takes a lot of solder.