So I just upgraded to a non ID 70-200 F/2.8L today. GREAT lens, and having f2.8 is UNHOLY! But.....well the blasted camera sucked it's battery down today. I was showing half charge when I got to the party I shot at(I got it in , didn't even get to open it, went to the party and started shooting LOL) today, and my battery is pushing dead at this point. That's very unusual, probably twice the batt consumption I'm used to(I had it on for maybe an hour, took approximately 50 exposures, no flash). Is it the lens or was my battery meter reading funny? If it's the lens, looks like I will be looking into a battery grip asap. I have a question on those as well. If I'm just looking for a larger capacity, should I just nab one of the cheap ones?