Soldering batteries into packs has been discussed several times here on RCU. Buying batteries with tabs that are designed to be soldered into packs if fine. Buying batteries from Radio Shack that are not designed with tabs is an iffy situation for someone that is not familiar with soldering. Not everyone knows how to properly solder. To much heat can and will destroy batteries. Even batteries with soldering tabs already fixed to the ends of the batteries should be carefully done because, again, to much heat will kill them.

I would not encourage someone to solder batteries together into packs unless they know how to solder and how to properly set the packs up for series operation.

CGr.