Summary

Charge cradle for extra batteries for Galaxy S2, May not work directly with your version, confirm battery contact locations and polarity.

Instructions

Basically what it says. Use a lithium charger unit like this:

http://dx.com/p/1a-lithium-battery-charging-module-blue-205188

It's designed to take DuPont breadboarding wires, with a tip bent in a J to catch in the channel under each hole. Solder the correct wire (+ or -) to the pads on the charger board and slip in a battery. The charger will turn off when charged.

YOU MUST USE A LITHIUM CHARGE CIRCUIT LIKE ABOVE OR YOU WILL NEED A FIRE EXTINGUISHER OR A NEW HOME.

Galaxy S2 Battery Charge Cradle