I use rechargeable AAs, better than going thru alkalines. Rechargeables help servo performance since NiMh holds voltage better than alkalines. I stated with 2dozen of these and the MH-C204 charger, but I was also sharing them with my digicam. They were worth the money, lasted over 5years. The Powerex brand AAs won a AA battery competition a couple of yrs ago that was sponsored by digicam industry group.

http://thomasdistributing.com/shop/-...ps8dcsvk48ju62

There are a lot of other rechargeable AAs out there, many charger options as well. I experimented with chargingmine with my rc charger using a 4 and 8 cell holder, but never liked the charge they got that way.