Questions about the buletooth keyboard and batteries

I just brought a mode a1314 bluetooth keyboard, and 6 apple batteries, but after full charged (about 5 hours, the charger shows with green light), but the keyboard still cannot work and shows low battery, is there something wrong with the keyboard?

I use this keyboard paired to my Thinkpad for working, in Window 7, and already installed the driver for keyboard.

Thanks a lot.