IBM Lenovo have software to monitor and control battery recharge, capacity.

[Lawsen]

I got the battery gauage software to calibrate to the actual current and voltage of the aftermarket Sanyo Electric LiMn2O4 battery.  I got it to set at 80% capacity, a good 10% improvement from 18 Wh to 20 Wh.  The theoretical limit is 25 Wh.  It seems to limit it 10% less than the theoretical for a safety margin to prevent over heating the LiMn2O4 battery.  20 Wh will give the tablet PC run time around 1 hour and 50 minutes, just 2 hours for a compact, smaller, and lighter battery.  I Pad 2 has the advantage of 8 hours theoretical run time, but actual run time is more like 6 hours and needs replacement every two years.  The actual is not the same as theoretical specifications written on the brochures.  You have to try it, before knowing it like tasting food, trying clothes, test riding and driving.  I tilt the tablet PC up to exposed the battery surface to air for better cooling during the calibration and discharge and recharge, keep the battery as cool as possible.  I fixed it.  

The Lenovo IBM battery monitoring and recharge software is conservative to prevent the overheating and fire of the Sanyo Electric LiMn2O4, lithium di manganese tetra oxide battery.  Li ion is generic name of large variety of ionic chemistry compounds and endurance, electron density capacity, internal resistance, and safety.  I used another X41 set for a larger capacity battery to condition the lower capacity battery to give it a full charge and recalibrate the X41 software that is under charging the battery.  The problem is only aftermarket batteries are available for six years old X41.  Lenovo IBM no longer support vintage tablet PC.  

Lawsen