Patent ID: 7282814

Claim:
An apparatus for charging and discharging a plurality of batteries, said apparatus comprising: a plurality of batteries; a plurality of direct current to direct current (DC to DC) converters, each DC to DC converter comprising load-side terminals and battery-side terminals, with the load-side terminals of the DC to DC converters being connected to each other in series, and, each battery of the plurality of batteries is electrically connected to the battery-side terminals of a respective DC to DC converter; and a co-ordinator connected to each of the plurality of DC to DC converters for controlling charging and discharging of the battery electrically connected to the respective converter; wherein the series connected load-side terminals of the plurality of DC to DC converters are electrically connected to at least one load and the co-ordinator co-ordinates the transfer of electrical power from the plurality of batteries to the one or more loads; wherein the co-ordinator sends a first control signal to a first converter of the plurality of DC to DC converters to cause the first converter to discharge a first battery of the plurality of batteries, the first battery electrically connected to the battery-side terminals of the first converter; and wherein the co-ordinator monitors the discharging of the first battery to determine characteristics of the first battery including its electrical capacity.