Making my own a123 battery packs and i broke off one of the solder tabs. Can the tab be fixed back on the battery so solder will stick, this is for the reciver so needs to be safe?? thanks for the help frank

Yes you can solder it back on or solder a wire direct to battery.Firstclesn a spot on the battery where you want solder to stick with a small piece of fine sand paper then apply a tad ofsolder paste to area.tin this spot with your soldering iron and a little solder.You can then solder a wire to the battery.I have made a lot of battery packs years ago with batteries that did not have soldering tabs on them.Be sure and use just enough heat to flow the solder to the battery with a shinny looking joint.

Be sure and use just enough heat ? will to much heat damage the cell thanks frank

Problem. A123 cells have an aluminum case. Sometimes, if you jsut clean them with a chemical rather than sanding you can get away with traditional soldering. Otherwise you'll need to go to welding supply store and get aluminum soldering paste from them (hardware stores don't carry this).
Walt

Problem. A123 cells have an aluminum case. sometime if you clean with a chemical rather than sanding you can get away with traditional soldering techniques, otherwasie you need to go to a welding supply store and get an appropriate flux (hardware stores do not carry this).
Walt

I was about to state that can't solder aluminum but you clarified that for me. Now I can get my node connectors put on hooray.

I used to solder up all of my battery packs. I had learned to solder by building my own Heath Kit TV set and later my own 8 channel single stick Heath Kit R/C radio. About 8 years after I put together my Heath Kit R/C radio I crashed a plane due to total loss of signal and found a cold solder joint at a battery solder joint (I believe I had replaced one of the four batteries in the pack). I could have killed someone with that plane, including myself. I was very good at soldering, but sometimes I did not solder for a few years. That was my problem. After that crash, back in 1981, I have never soldered a battery pack again. Now I always purchase complete battery packs and I believe I am much happier for that. I also sleep better.