Hi all. After almost two years of hiatus (with a few shots occasionally), I have dug out my dSLR again. The problem is that my batteries are not holding a charge particularly well. I give them a full charge, but after 30-50 exposures they're empty. When I try to charge them, the charger read full (steady light) after no more than a few minutes. I will keep the batteries on the charger for a while for good measure, but it does not increase their life. I don't use the LCD on the back to look at the images, so that isn't drawing any power. It's a Canon 5D. I have three batteries, two of which are older, from my Canon D60. Do I just need to bite the bullet and get a new battery or two?