We are using
1. The delivered charger with hte EduBot.
2. A PF12 (Park-Flyer) charger from Hobby People.
www.hobbypeople.net
search for chargers.
The PF12 is a great charger as all you need to do is dial in the amperage you want and press a button.
The Edubot batteries are 800mah. You set the PF12 to 2c or 1600mah and when the battery is "full", the unit switches to a trickle charge. (1/10 dial setting)
You will need Adapters for the Battery packs (r/c cars use something similar.)
Good Luck.
Phil