i have 15% wear level, i got the laptop in may, I dont use it on batts that much, just @ school. Yesterday my meter in windows said my primary batt was 100% yet windows was giving me a low battery warning... and then it just shut down. I tired to start the laptop again it would not as if the battery was flat. I had to put it on the charger, when i went back into windows with the AC plugged in, windows again stated that the battery was @ 100%.