heating & charging

here're some observation of heating & charging status on android.

• if the device is heating, baterry discharging is faster. cooler status around 30 degrees is better and normal.
• if USB charging causes heating, battery may have issue.
• normal USB charging will not cause heating. wireless charging may increase 10+ degrees, to about 40-50 degrees.
• abnormal app behavior may cause charging stop, which may sometimes induce abnormal heating.
• USB and wireless charging are different mechanisms, which could be used to check verify physical status with each other.