Battery tab welding?

[BioHazard]

As some of you have noticed I have a huge surplus of AA NiMh batteries. I'd love to make some higher voltage battery packs out of them, trying to rebuild some power tool packs. I have seen plans online for a capacitor discharge spot welder for welding nickel tabs to batteries. They charge a big capacitor bank up to about 25v for the spot weld through 2 copper electrodes.

Would this work with 2-3 car batteries wired in series instead of capacitors? That would be a lot easier for me to find in my junk pile. Anybody ever weld battery tabs before?

Also, what thickness of nickel should I be using on the batteries? I'll need to buy a small sheet. Or does somebody sell pre-cut battery tabs? Google hasn't given me a lot of info.

[mike90045]

DON'T use a car battery.  Wayyy  toooo  much power !!  you will vaporize the tab and the cell.


tab welder battery pack   yields:

http://ledhacks.com/power/battery_tab_welder.htm

http://ledhacks.com/power/tab_welder%20ii.htm

http://www.rcgroups.com/forums/showthread.php?t=763308

http://www.philpem.me.uk/elec/welder/

   and many more.