Here is some updated video on the unity recharger. Ran 2 weeks, swapped the main bats with the charging bats. Some meter readings and such in the video. Letting it run again to recharge the main bats that drained on the first run. http://youtu.be/3bVzI58k-Dk (http://youtu.be/3bVzI58k-Dk)
The two running batteries are labelled NiCd's, the two charging batteries look like NiMH. Are you mixing battery chemistries?