Patent ID: 7626359

Claim:
An apparatus comprising: a plurality of serially-connected bypass circuits, the bypass circuits being electrically connectable in parallel with a plurality of serially-connected batteries, each bypass circuit being electrically connectable in parallel with a respective battery, wherein each of the batteries includes positive and negative terminals, the batteries including main terminals each of which is electrically connected to a respective one of the positive terminal of the first battery and the negative terminal of the second battery, and one or more intermediate terminals each of which is electrically connected between a respective pair of the batteries; a measurement/control element electrically connected to the bypass circuits, and electrically connectable to the batteries, wherein the measurement/control element is configured to measure voltages across the respective batteries and, based on the voltages, selectively operate the bypass circuits to divert electrical current to or from the batteries through the respective bypass circuits; and a plurality of safety circuits electrically connected to the measurement/control element, and electrically connectable between the measurement/control element and the batteries, wherein the plurality of safety circuits includes a separate safety circuit for each of the main terminals and each of the one or more intermediate terminals, each safety circuit being electrically connectable in line between the measurement/control element and a respective main terminal or intermediate terminal, and wherein each safety circuit is configured to limit current flow to the measurement/control element.