Also, if it helps, I forgot to mention that when I put the battery in the charger, I notice the light always blinks 6 times at the normal "pack charging" rate then starts blinking rapidly at the "replace pack" rate.
The 6-8 blinks is the normal communication with the battery and charger, if everything goes well the charger will start it's charge cycle, if not then it blinks rapidly to indicate a bad pack.
You can take the pack to a service center to get a replacement, but i am curious about the low charge cycle and it might be an internal issue so it you want you can send it to me and i can get you a replacement....
FYI.... The serial number has all the info about production date code, location, and cells.