there are 3 channels for the AA, A B and C, they're all on the 27mhz frequency. if you both have the green one, you're probably on the same channel. its possible to switch channels, but it takes a good steady hand and some OK soldering skills.

the AAs have a 130mah lipo cell. all lipos have a nominal voltage of 3.8 volts, with a max of 4.2 and a minimum of 2.8 (never discharge past 2.8v or the cell will be ruined). i cant remember the capacity off hand, but i'm quite certain its at least 10C, so you have a little over an amp to play with.

nick