The battery I got with my Canon 5D MkII When Fully Charged lasts me Roughly 10 hours when on and photographing a wedding but this battery When fully charged lasted Roughly 4 hours in the same situation. Plus When I received it I had to question its authenticity as it arrived just wrapped in a cellophane type small bag with no Canon Packaging, No Canon guarantee, and no instructions, not that u need instructions but Usually everything comes with instruction info and for sure a guarantee. Next time I will pay the extra money and buy it at a proper camera shop. Stay away!
