Energy storage system with green maintenance discharge cycle
An energy storage system with an energy storage cell coupled to a battery management system provided with a charge control circuit, a discharge control circuit and a maintenance discharge control circuit. The maintenance discharge control circuit including a voltage booster coupled to a constant current/constant voltage (CC/CV) regulator. Each of the charge control circuit, the discharge control circuit and the maintenance discharge control circuit are coupled between the battery management system and a host power rail. The voltage booster is operable to raise a voltage from the energy storage cell to a CC/CV regulator input voltage greater than a voltage of the host power rail, enabling the CC/CV regulator to provide a selected maximum voltage and corresponding maximum current to the host power rail during a maintenance discharge cycle of the energy storage cell.
1. An energy storage system, comprising
an energy storage cell coupled to a battery management system provided with a charge control circuit, a discharge control circuit and a maintenance discharge control circuit;
the maintenance discharge control circuit including a voltage booster coupled to a constant current/constant voltage (CC/CV) regulator;
each of the charge control circuit, the discharge control circuit and the maintenance discharge control circuit coupled between the battery management system and a host power rail;
the battery management system operable to enable each of the charge control circuit, the discharge control circuit and the maintenance discharge control circuit for interconnection with the energy storage cell;
whereby the maintenance discharge control circuit is adapted to perform a deep discharge cycle upon the energy storage cell.
2. The energy storage system of claim 1 , wherein the voltage booster is operable to raise a voltage from the energy storage cell to a CC/CV regulator input voltage greater than a voltage of the host power rail.
3. The energy storage system of claim 1 , wherein the CC/CV regulator is a buck converter feedback loop.
4. The energy storage system of claim 3 , wherein the CC/CV regulator has both current and voltage feedback loops.
5. The energy storage system of claim 1 , wherein the CC/CV regulator is operable to deliver a maximum voltage and a maximum current to the host power rail.
6. The energy storage system of claim 1 , wherein the CC/CV regulator includes an integrated communications link.
7. The energy storage system of claim 6 , wherein the battery management system is operative to provide a set-point to the CC/CV regulator via the integrated communications link.
8. The energy storage system of claim 1 , wherein the battery management system is operable to perform a maintenance discharge cycle until the CC/CV regulator no longer receives a voltage greater than a voltage of the host power rail.
9. A method for maintenance discharge of an energy storage cell coupled to a battery management system provided with a charge control circuit, a discharge control circuit and a maintenance discharge control circuit coupled between the battery management system and a host power rail, comprising:
passing an output voltage of the energy storage cell through a voltage booster and into a constant current/constant voltage (CC/CV) regulator of the maintenance discharge control circuit to perform a deep discharge cycle upon the energy storage cell;
the voltage booster raising the output voltage of the energy storage cell above a voltage of the host power rail; and
delivering a selected maximum voltage from the CC/CV regulator to the host power rail until the energy storage cell is discharged to a desired power level.
10. The method of claim 9 , wherein the CC/CV regulator is a buck converter feedback loop.
11. The method of claim 10 , wherein the CC/CV regulator has both current and voltage feedback loops.
12. The method of claim 9 , wherein the CC/CV regulator is configured to limit a maximum current and a maximum voltage delivered to the host power rail.
13. The method of claim 9 , wherein the selected maximum voltage is delivered until the CC/CV regulator no longer receives a voltage greater than a voltage of the host power rail.
14. The method of claim 9 , wherein the selected maximum voltage is delivered until a pre-selected minimum output voltage of the energy storage cell is detected.
15. The method of claim 14 , wherein the minimum output voltage is determined by a battery chemistry of the energy storage cell.
16. The method of claim 9 , wherein the selected maximum voltage is delivered until a pre-selected temperature of the energy storage cell is detected.
17. The method of claim 9 , wherein the selected maximum voltage is delivered until a pre-selected time interval has passed.
18. The method of claim 9 , wherein the CC/CV regulator includes an integrated communications link.
19. The method of claim 18 , further including a battery management system monitoring a status of the energy storage cell and providing a set-point to the CC/CV regulator via the integrated communications link.
20. The method of claim 19 , wherein the status of the energy storage cell includes at least one of an energy storage cell voltage, current, cycle count or temperature.