float getSoC(); 

FuelGauge fuel;
Log.info( "SoC=%.2f", fuel.getSoC() );

Returns the State of Charge in percentage from 0-100% as a float. Returns -1.0 if the fuel gauge cannot be read.

Note that in most cases, "fully charged" state (red charging LED goes off) will result in a SoC of 80%, not 100%. Using getNormalizedSoC() normalizes the value based on the charge voltage so the SoC will be 100% when the charge LED goes off.

In some cases you can increase the charge voltage to get a higher SoC, but there are limits, based on temperature.

Since 1.5.0:

It may be preferable to use System.batteryCharge() instead of using getSoC(), which uses the value in device diagnostics, which eventually uses getNormalizedSoC().