A portable information handling system manages battery charge to maintain a minimum level that supports boot by disconnecting the battery from a battery discharge path so that battery charge is lost substantially only to self-discharge. The battery automatically reconnects to the battery discharge path if external power becomes available to charge the battery. The minimum battery charge level provides adequate power in combination with the external power to support boot of the portable information handling system to an operational state. A power manager monitors power transition events to track power consumption information that a battery charge manager applies to modify the power transition events if external power and available battery charge are not sufficient to perform the power transition event without modification.