Battery Packs
 

Ive just bough 12 Nosram P-Max VTEC SC-4200 Big Mama battery packs. I have never built-up my own battery packs. Ive been told to use a 100w soldering iron, so as not to overheat the batteries. Whats should I use to physically connect the batteries together?

battery bars would be nice..

I use silver tin, without resin, and some stuff called 'Purine' it's a soldering grease.. I put some purine between the bars and the batteries, and i made something that presses the bars onto the two batteries it needs to connect. Just heat it up with a soldering iron that is pretinned.. The tin just floats between the bar and the battery. add some more tin if needed.

Don't pretin the bars/batteries, It will be impossible to solder them on straight, unless you use two soldering irons..

If you heat them up with such a large iron, the cell won't be as hot as with a smaller 25W.. My cells are about 35 degrees C 10 secconds after i soldered them.