First some facts:
- The BG-E2 with 2x Canon BP511 Li-Ion batteries lasts for 4 hours continuous shooting. Power indicator showed full.
- The BG-E2 with 6x 2500mAh NiMH batteries lasts for 3.25 hours continuous shooting. Power indicator showed half-full.
I was expecting a longer shooting time with the AA batteries, however I have found the problem of this being 1.2v rechargable AA batteries instead of the 1.5v disposable AA batteries which it was designed for.
Now, the Canon BP511 battery has a voltage of 7.2v, and the 6x AA NiMH also have 7.2v, so in theory, the AA batteries should last longer as they have more capacity. But they do not - which leads me to think that the wiring of the Canon batteries versus the AA batteries is different.
If this is true, can the BG-E2 be re-wired for AA batteries to *trick* the camera into thinking that a BP511 is attached ? It seems that the low-power cut off kicks in sooner for AA batteries than the Canon batteries.