I was checking the battery condition using my battery life feature on my Nikon D2Xs camera. The battery indicator pointed out that I needed to calibrate my battery. The indicator message read as such, eg: Calibration Required! in red letters. So I placed this battery on my Nikon MH-21 charger, after plugging it in, I selected the calibrate button. It took quite awhile for this process, and from what I know about the calibration process, the charger basically drains all the charge during the calibration. Then recharges until fully charged. The charger is supposed to auto re-charge the battery once all the power is drained during the calibration process. When I woke up to check the battery status on the charger the next morning, the green 50% light was flashing under the charge level and to the right of that on the calibration side it was indicating 2h. I then checked the battery in the camera and it was essentially dead!!! I tried re-inserting the battery in the charger and simply performing a straight charge, but all the charger does is flash green at 50% and won't charge. Normally all the charge lights light up on a normal charging and then then they extinguish down to the actual battery level eg: 50% then the charger should commence charging. But my battery all it does is flash 50% and no charging!!! Please advise, since the MH-21 operator manual is very brief and doesn't have any troubleshooting guide for this issue. I look forward to your reply, thanks.