Get rid of the problematic Ni-cads

Go to Wal-Mart and buy the NiMh rechargeables.
They are the same type of battery that digital cameras
often use. The have no real memory effect and are
cheaper than N-cads. You can usually find the batteries
sold with a charging unit. I have found a four AA battery
charger with four batteries for as low as $10 at Wal-mart.

You can also browse http://www.thomasdistributing.com/