Panasonic Evolta AA Rechargable Batteries with 50 more mAh and 100 more recharges than Sanyo Eneloops.
It appears to be 5 x 2 packs of AA batteries. AAA is available for $26.95 containing 8 batteries.
These batteries are 100% compatible with Sanyo Eneloop chargers.
http://www.youtube.com/playlist?list=PL280443A808F234EE
It's a 2 hour 30 minute playlist, but long story short three different Evolta robots completed a Iron man Triathalon using three rechargable evolta batteries. The course was 230km long.
I highly recommend the Hobbyking LSD AA rechargeable batteries. I have used them for years and they have been faultless.
http://www.hobbyking.com/hobbyking/store/__10456__Turnigy_AA…
Rated at 2200mAh, but have always come in over that (one batch was up around 2400mAh!). These have out performed my eneloops in my camera.
At $1.29 each plus shipping, the sweet spot is to order them in lots of 14:
8 x AA Batteries for $17.32USD delivered ($2.165 USD ea)
14 x AA Batteries for $28.06USD delivered ($2.00 USD ea)
21 x AA Batteries for $42.09USD delivered ($2.00 USD ea)