My personal experience is to have AA batteries instead of any other 3rd party BP511As. Since the BG-E2N comes with an AA magazine, I always load 6 fully charged AAs inside and carry it around. I also have back up AAs, for both my cameras and the flash units. Alkaline AAs are also easy & cheap to buy when there isn't any handy power for charging the BP511, though they don't last too long for digital cameras it's better than nothing when I'm out of power.


Since I have to carry AAs for my flash unit anyway, I'll just use AA for alternative camera power supply. I assume it makes sense.