[redpoint5]

I have both a Roomba and Neato robotic vacuum cleaners that use NiMH battery packs. After just over a year with the Neato, the battery only runs the robot for 5min before it heads back for a recharge. The Roomba only runs a few seconds.

I also have a Lacrosse NiMH battery charger that has features for testing individual cell capacity and refreshing weak cells. The problem is that it's designed to accept only AA and AAA sized cells.

I'm wondering how I can best test the larger welded cells in the robot packs? I don't want to destroy the pack by cutting the welded tabs, and I haven't found a device that can clamp onto the ends of the cells.

Any ideas how best to balance charge and test the cells? I'd be willing to buy other chargers and testers since I plan on needing to do this more in the future. I was thinking it should be possible to connect leads to individual cells in the pack and then connect those leads to the Lacrosse. I am able to open the Lacrosse charger up and get alligator leads onto the charging contacts, but connecting them to the cells is problematic. Would there be any issues connecting a larger capacity cell to the Lacrosse than it was designed for?