Why do the rechargeable batteries (NiMH) in my digital camera wear down so quickly...is it the batteries?

Sometimes there is bad battiries out there. The other thing to is if you plug them into the wall and leave on the charger for longer then just to charge them soemtime that will wear the battery down to. The other thng is how many pictures do you take? If your taking a ton then maybe its normal.

yeah try new ones

it is because you may be reviewing the photos often and reducing the battery.however you recharged them ; they are not as new and powerful as you first bought them.so, they do not work to your expectations.

yes, they need to be completely discharged and recieve a full charging. the discharge is the trick. you'll have to build something , maybe with a low voltage light bulb to do it.