Patent ID: 9658290
Date: 2017-05-23
CPC Classifications: G01R,G08B,H01M,H02J,Y02E

Claim:
1. An apparatus comprising: a plurality of batteries; a plurality of switches electrically coupled to the plurality of batteries; a power bus electrically coupled to the plurality of switches; voltage measurement circuits coupled to the plurality of batteries to separately measure a voltage output from each of the plurality of batteries; switching circuits that control the plurality of switches to selectively switch among the plurality of batteries so that only a single battery of the plurality of batteries is electrically coupled to the power bus for a predetermined percentage of a predetermined time interval; and a microcontroller electrically coupled to the voltage measurement circuits and the switching circuits to track a total connection time that each of the plurality of batteries is coupled to the power bus by the switching circuits, wherein the predetermined percentage of the predetermined time interval for one of the plurality of batteries is greater than the predetermined percentage of the predetermined time interval for other batteries of the plurality of batteries, and wherein the voltage measurement circuits determine when the one of the plurality of batteries has been discharged, and, responsive thereto, the microcontroller calculates a remaining lifetime for each of the other batteries of the plurality of batteries as a function of the total connection time for each of the plurality of batteries.