The above circuit will charge any 2-cell * Li-Ion battery pack.
Maximum current is about 650 milliamps.
The circuit is designed for batteries of 900mah or higher. Note this circuit is NOT for Li-Metal batts (i.e. Duralites).
Power source can be a 12v Gell cell (Power panel), or can be powered by a car’s cigarette lighter.
I use an old 12v DC wall transformer (800ma or more.) Radio shack sells a 12v/1amp wall DC adapter #273-1776 that will work.
Supply does not need to be regulated. In fact my cheap supply outputs 17 volts with no load.