Patent ID: 8497600

Claim:
A system for providing supplementary or emergency power, the system comprising: a battery circuit connected to a battery circuit node, wherein the battery circuit node is configured to provide battery power, and wherein the battery circuit comprises— multiple battery strings, wherein each battery string comprises: one or more batteries coupled in a series configuration; and at least one switch circuit configured to selectively couple the one or more batteries to the battery circuit node, wherein the battery circuit node is configured to provide power, and to receive a charging current for charging batteries; and a power controller configured to: selectively couple one or more of the multiple battery strings in the battery circuit to the battery circuit node, wherein a battery string coupled to the battery circuit node operates as an active battery string, wherein the active battery string provides via the battery circuit node, and wherein the active battery string actively receives the charging current to maintain the active battery string at or near a full charge; selectively decouple at least one of the one or more of the multiple battery strings in the battery circuit from the battery circuit node, wherein a battery string decoupled from the battery circuit node operates as a parked battery string, wherein the parked battery string does not actively receive the charging current; and, upon an occurrence of a battery change event, to— (i) couple the parked battery string to the battery circuit node to provide power and to actively receive the charging current; or (ii) decouple the active battery string from the battery circuit node and to no longer receive the charging current; or (iii) both (i) and (ii); and, wherein the battery change event includes at least one of a specified charging event, a specified testing event, or a power failure event.