Originally Posted by jph
What is the best temperature to solder batteries?
The hotter, the better, since it will melt the solder in the shortest time. The idea being that you want to melt the solder and heat the battery bar / wire, but not the cell. Ideally, you'd like to apply the heat for 2 - 3 seconds and that's it. Use a battery making jig like the Deans or Venom one to hold the battery bars in place.
A quick primer:
1) Scuff or lightly sand the cell ends
2) Clean the cell ends with motor spray
3) Place cells in battery jig in correct orientation
4) Pre-tin the cell ends
5) Allow cells to cool
6) Use jig hold battery bar(s) in place
7) Apply heat and possibly more solder so that bar "sinks" in puddle of melted solder (one end of battery bar at a time, no more than 3 seconds each)
8) Allow cells to cool
9) Flip jig over and do the other side
10) Allow cells to cool
11) Apply a small amount of Shoe Goo between cells to help hold them together if desired
MuchMore makes a neat jig to help solder tabs on to the cells to solder your wires to, and pre-bent battery bars for the tabs.