Originally Posted by oxford_artist
The K100D is a bit choosy about batteries. If you search this site on batteries, you will find lots of explanations and advice. Personally, I use rechargeable Uniross Hybrios and Sanyo Eneloops, both work very well. I bought the Eneloops at a camera shop because I'd forgotten to take a back up set for the Hybrios when on a shoot. The assistant recommended another set of rechargeables with a higher rating that he used in his Pentax (I wish I could remember what they were called) but I took the Eneloops because, like the Hybrios, they come ready charged. The big advantage with both is that they keep their charge longer when not in use, ordinary NiMH batteries have a serious fall off of charge over time even when not used.
Well in that case I hope that my GP 2500 are good enough then, I did see that my local shop sells the Uniross ones (never heard of them before I saw them on the website of the store) but not the Hybrid ones just the plain HiMh batteries that come "empty".