How to Judge Mobile Battery Remaining Capacity

Definition of Lithium Battery capacity: after fully charge battery according to regulation and constant current discharge to cut-off voltage, product of discharge time and discharge current is lithium battery capacity.

For example, if a Lithium ion Battery is fully charged(4.2V) and it takes 65 minutes to discharge the battery to cut-off voltage 2.75V with 800mA current, this battery capacity is 800mA*?65/60?h=866mAh.

During discharge, Battery Voltage will drop as battery remaining capacity declines. There is a simple and effective corresponding relationship between voltage and capacity. Through battery charge & discharge tester, we get a mobile battery 50mA discharge curve, divide discharge time to 4 equal parts, take charge limit time 4.2 lithium ion battery for example, corresponding relationship as below,

4.20V—-100%

3.95V—-75%

3.85V—-50%

3.73V—-25%

3.50V—-5%

2.75V—-0%

We could monitor remaining capacity with mobile battery voltage. The method is: on mobile hidden menu, check battery voltage via engineer model, like Samsung mobile phone, Waveguide S120 & S1000 etc. Above corresponding relationship will be change for different kind of battery, different manufacturer, therefore, similar on basis, for your information.