How long you battery last? I don't think the draining of the batteries has anything to do with the slow writing speed to the SD card. In my experience, for Kodak cameras, the speed of the card does not matter much, I've tried from class 2 to 10, and really did not notice the different. The slowness is the camera. Beside the more pictures you have in the card, the slower the camera. So I transfer all the pictures when there about 150 pictures in the card.
Sanyo Eneloop work very well for me.
Nikon D5000 / Kodak Z990 P880 DX7590 Z915 DX6440 V803 M420 C190 C875 Zx3
Kodak Digital Cameras Galleries