I had same problem with my Olympus digital camera. Some of the cheap batteries would go flat just putting the menu on, branded ones may take 1 or 2 pics, and duracell maybe 3 pics. I have a couple of 1000mAh batteries I picked up in poundland (ideal spares), 4 uniross 1700mAh and 4 uniross 2000mAh. The batteries must be Ni-MH, not ni-cd. The charger I got from currys lets you charge batteries at home (via mains) or in the car using the adaptor that goes in the cigar lighter socket.