Battery Calibration

This screen shows a summary of battery data and it's calculated capacity based on recorded data.

Historical data shows maximum mV and % from recorded data.

Avg on-off shows average use-time with screen on or off.

The calendar view (default) can be switched to history by simply tapping on it (or using the top-right menu). It shows charged amount per day, a color-coded cycles count (1 = green, 2 = yellow, 3 = orange, 4+ = red).

The in-use mAh is the capacity currently used by the app to do its calculations.

The average mAh is determined from recorded data, only from charge cycles for more accurate results (experience shows that discharge cycles are highly inconsistent because of possibly inconsistent hardware sensors).

The total charged shows total mAh/% charged (from recorded data) and recorded charge cycles, and on supported devices hardware charge counter. Those may differs widely (see screenshots above), because app has been installed after many charge cycles or if small charge cycles are used but not considered as full hardware charge cycle. The hardware charge cycle can help determine battery aging and confirm average mAh calculated. Note that batteries in modern mobiles devices are considered to last about 500 to 700 cycles before their capacity drops significantly.

The table shows all charge cycles but will only consider cycles larger than 30% when calculating estimated capacity (mAh).

Each charge cycles considered are listed and may be adjusted (on devices with estimated mA) as described here (you may have to adjust USB or AC power in battery / calibration settings if necessary):

• The charge rate was higher than the defined USB power

• The charge rate was higher than the defined AC power

Those errors are measured against AC/USB power capabilities (as defined in battery / calibration settings), only on devices with estimated mA. Either the power capabilities are incorrectly configured or the actual (in-use) battery capacity is overrated.

Read more here: How does calibration works?

For information on how to prolong your battery life, here is an interesting Wiki (see battery life chapter). 

The important points are those 2:

-Keep battery cool, and avoid charging past 70% while using the device and creating over-heating.

-Avoid discharging your battery fully, except if calibrating because of incorrect % reported.

Additional options are available pressing the menu button:

• Clear history
• Clear battery statistics (need root)
• Clear estimates