[69L46]

Might be a bad battery. Lithium-polymer batteries are charged at a constant current until they get to a cut-off voltage (usually 4.2V). Then they are charged at that cut-of voltage until the charging current drops to a cut-off current (usually something like 50-100mA). On discharge, the voltage ddrops rapidly to a plateau voltage that is the nominal voltage printed on the battery. This is 3.7V (3.4V for Li-ion). Charge it and then pull the battey and see if you can measure the voltage. It should be something close to 4.2V (I'm assuming it's a Li-polymer battey. If the voltage is good, it's probably a calibration problem (I assume the procedure that ShadowDrake described is designed to do this). If the voltage immediately after charging is closer to 3.7V, then either the battery is bad or the phone is measuring the incorrect cell current/voltage (probably the former rather than the latter).