I thought I would check out how long the 5D2 would last under AA power. I put 6 freshly charged Varta NiMh 2500mah into the grip and immediately the power level showed only 2 bars. I flicked into record mode and after maybe 10 secs I got a complete flame out.

Wonderful....

So I removed the AA tray from the grip and crossed a DVM over the terminals and it read 8.2 volts. This is strange because a single LP-E6 battery is rated 1800mah at 7.2 volts.

I checked over the instructions for the grip and it says it will work under AA power with Alkalines - no mention of NiMH...

I conclude the grip somehow knows there are NiMH in there and refuses to cooperate, maybe the internal resistance is different from NiMh to Alkaline.

Maybe your findings are different , please share.

I'd check mine to see if it behaves the same, but my dog ate the AA battery cartridge only a few days after I got my bg-e6.

Have not had a problem with eneloop nimh and knock off grip - lots of power!

I second the previous poster's statement. Eneloops AA's work just like normal batteries, they worked great in the grip.

-David