How I can calibrate battery of my Proscenic NEO 820p robot? I bought in last november and used 10 times, the robot is aways charging in base, but when I use it now it have no battery, it shows 100%, but when I put it to clean, he shutdown in a few minutes(20minutes), then I put to charging again, then power up,  and show 90% battery. I try to remove battery, put again, but is show wrong battery level. I think it is an firmware problem, because in last firmware it self discharge in base, and in actual firmware it don't ocurred, maybe last firmware discalibrated my battery.