I dont know. I got the second battery with a used Dell Mini which I used for parts.
I am on Mac OS and I used System Profiler to check both batteries. System Profiler says the total capacity of the good battery is 2200mAh and the capacity of the bad battery is only 1750mAh. The good battery has been charged 15 times and the bad battery 10 times.
If a cell was bad it would have lower voltage and would not work.
I am going to have to find out if there is a way to recalibrate the battery.
I dont think the Fn + battery key works on Mac OS.
I have another SSD
with windows installed on it. I might give that a try...