Abstract: A backup power system for household or structural appliances that normally receives power from a primary power source, and is not an uninterruptible power system. Included are batteries, a battery charger, a power interface interconnecting the primary power source and the backup power system, power relays that comprise a switching matrix of individually operating relays that connect and disconnect the sources and appliances one and only one at a time, sensing devices to monitor the currents and voltages, conversion of the DC voltage of the batteries to AC voltage for backup power to the appliances, circuitry for preventing peak power demands by delivering sequentially selected appliances, one and only one at a time and only when power is demanded by each individually selected appliance, thereby prolonging the operating lifetime of fully charged batteries.

Abstract: A backup power system for household or structural appliances that normally receives power from a primary power source, and is not an uninterruptible power system. Included are batteries, a battery charger, a power interface interconnecting the primary power source and the backup power system, power relays that comprise a switching matrix of individually operating relays that connect and disconnect the sources and appliances one and only one at a time, sensing devices to monitor the currents and voltages, conversion of the DC voltage of the batteries to AC voltage for backup power to the appliances, circuitry for preventing peak power demands by delivering sequentially selected appliances, one and only one at a time and only when power is demanded by each individually selected appliance, thereby prolonging the operating lifetime of fully charged batteries.