Gripped 7D--AA battery life

Anyone with experience using the 4-pack AA-tray in a grip with a 7D? In particular, I'd very much like to know how many stills, and how many minutes of video recording you can get on a set of AA's. I've got like 32 eneloop AA's

I've never ever tested with AA trays in any grips. I've always survived a day with 2 proprietary batteries. But, I may be lending out my 7d for use at a wedding for video recording, along with my new Rode Videomic--and the 2 LP-E6's I have may not be enough. AC Coupler is not an option.

Any information would be helpful. If necessary, I can figure out video recording minutes from still-shot counts.

TIA

I tried AA's in my old 20D grip and they lasted about 20 shots!

Maybe they ahve changed things a lot in the new model grips, but I don't think it is meant to be used for long periods of time with AA's, but is a 'get-you-out-of-trouble' solution, as you can purchase a set of these almost anywhere in the world.

6 eneloop AA is approximately equal to 1.5 LP-E6 in theory, though I have never tried AA batteries in grip.

As a typical days shoot is about 1k of shots at the track over typically 9 hours I've never used the AA's in the grip, always stuck with the 2 batteries in the grip which does the distance no problem.