I have a D80 and recently purchased a D90. I seem to be having a problem with the D90 though. I have 2 Nikon batteries and 2 aftermarket batteries. The aftermarket batteries work fine in the D80 but show as almost dead in the D90, even after a full charge. The battery meter in the D80 shows these batteries at 100% charge but the D90 won't power up and the battery indicator in the top LCD shows their just about dead. Both Nikon batteries work fine in the D90 though. Is this an incompatibility ??? I called Nikon but since their aftermarket batteries they won't comment. Anyone else run into this problem with aftermarket batteries ????? Thanks Brian