Rechargeable battery systems and rechargeable battery system operational methods
View Patent ↗Rechargeable battery systems and rechargeable battery system operational methods are described. According to one aspect, a rechargeable battery system includes a plurality of rechargeable battery cells coupled between a plurality of terminals and shunting circuitry configured to shunt charging electrical energy around respective ones of the rechargeable battery cells during charging of the rechargeable battery cells from substantially discharged states of charge of the rechargeable battery cells to substantially charged states of charge of the rechargeable battery cells.
1. A rechargeable battery system comprising:
a plurality of rechargeable battery cells coupled between a plurality of terminals; and
shunting circuitry configured to selectively shunt charging electrical energy around respective ones of the rechargeable battery cells during charging of the rechargeable battery cells from substantially discharged states of charge of the rechargeable battery cells to substantially charged states of charge of the rechargeable battery cells;
wherein the shunting circuitry is configured to shunt different amounts of the charging electrical energy around different ones of the respective rechargeable battery cells as a result of the different respective rechargeable battery cells having different states of charge;
wherein the shunting circuitry comprises a plurality of shunting devices individually configured to shunt the charging electrical energy around a respective one of the rechargeable battery cells;
control circuitry configured to control shunting of one of the shunting devices using a control signal within a first duty cycle range and to control shunting of another of the shunting devices using a control signal within a second duty cycle range which is different than the first duty cycle range; and
wherein the control circuitry is configured to control shunting of the one and the another of the shunting devices corresponding to the states of charge of the respective rechargeable battery cells which are coupled with the one and the another shunting devices.
2. The system of claim 1 wherein the shunting circuitry is configured to shunt the charging electrical energy to increase balancing of the states of charge of the rechargeable battery cells with respect to one another compared with the states of charge of the rechargeable battery cells in an absence of the shunting.
3. The system of claim 1 wherein the shunting circuitry is configured to selectively shunt the electrical energy around the respective ones of the rechargeable battery cells during an entirety of the charging of the rechargeable battery cells from the substantially discharged states of charge to the substantially charged states of charge.
4. The system of claim 1 wherein the rechargeable battery cells individually include a plurality of different operational states corresponding to different states of charge of the individual rechargeable battery cell, and wherein the shunting circuitry is configured to shunt the charging electrical energy during all of the different operational states of the rechargeable battery cells.
5. The system of claim 4 wherein the different operational states include the substantially discharged state of charge, an intermediate state of charge, and the substantially charged state of charge.
6. The system of claim 1 wherein the shunting circuitry is configured to disable shunting of the one of the shunting devices as a result of a temperature of the one of the shunting devices exceeding a threshold.
7. The system of claim 1 wherein the rechargeable battery cells comprise Lithium.
8. The system of claim 1 wherein the control circuitry is configured to monitor states of charge of the rechargeable battery cells during an entirety of the charging of the rechargeable battery cells from the substantially discharged states of charge to the substantially charged states of charge, and wherein the shunting circuitry is configured to selectively shunt the charging electrical energy during the entirety of the charging of the rechargeable battery cells from the substantially discharged states of charge to the substantially charged states of charge as a result of the monitoring.
9. The system of claim 1 wherein the shunting circuitry is configured to provide maximum shunting with respect to one of the rechargeable battery cells as a result of the state of charge of the one of the rechargeable battery cells exceeding a threshold.
10. The system of claim 1 wherein the shunting circuitry is configured to provide increased shunting of the charging electrical energy with respect to one of the different respective rechargeable battery cells compared with another of the different respective rechargeable battery cells as a result of the state of charge of the one of the different respective rechargeable battery cells being greater than the state of charge of the another of the different respective rechargeable battery cells.
11. The system of claim 1 wherein the shunting circuitry is configured to shunt the charging electrical energy around different ones of the rechargeable battery cells at different moments in time during the charging of the rechargeable battery cells from the substantially discharged states of charge to the substantially charged states of charge.
12. The system of claim 1 wherein the shunting circuitry is configured shunt the charging electrical energy around different ones of the rechargeable battery cells at different moments in time.
13. The system of claim 1 wherein the shunting circuitry is configured to shunt the charging electrical energy around one of the rechargeable battery cells as a result of the one of the different respective rechargeable battery cells having a higher state of charge than another of the different respective rechargeable battery cells.
14. A rechargeable battery system operational method comprising:
using charging electrical energy, charging a plurality of rechargeable battery cells of a rechargeable battery system, wherein the charging comprises charging during a plurality of different operational states of the rechargeable battery cells including a substantially discharged state, an intermediate state, and a substantially charged state; and
shunting charging electrical energy around selected ones of the rechargeable battery cells during the charging of the rechargeable battery cells in the plurality of different operational states including the substantially discharged state, the intermediate state, and the substantially charged state; and
wherein the shunting comprises shunting different amounts of the charging electrical energy around different ones of the selected rechargeable battery cells as a result of the different selected rechargeable battery cells having different states of charge;
wherein the shunting comprises shunting using a plurality of shunting devices individually configured to shunt the charging electrical energy around a respective one of the rechargeable battery cells;
controlling shunting via one of the shunting devices using a control signal within a first duty cycle range and shunting via another of the shunting devices using a control signal within a second duty cycle range which is different than the first duty cycle range; and
wherein the controlling comprises controlling the shunting via the one and the another of the shunting devices corresponding to the states of charge of the respective rechargeable battery cells which are coupled with the one and the another shunting devices.
15. The method of claim 14 wherein the shunting comprises shunting during an entirety of the charging of the rechargeable battery cells from the substantially discharged state of charge to the substantially charged state of charge.
16. The method of claim 14 wherein the shunting comprises shunting to increase balancing of the states of charge of the rechargeable battery cells compared with the states of charge of the rechargeable battery cells in an absence of the shunting.
17. The method of claim 14 wherein the shunting comprises shunting to provide different amounts of the charging electrical energy to different ones of the rechargeable battery cells at a common moment in time during the charging.
18. The method of claim 14 wherein the shunting comprises shunting the charging electrical energy around one of the different selected rechargeable battery cells as a result of the one of the different selected rechargeable battery cells having a higher state of charge than another of the different selected rechargeable battery cells.
19. The method of claim 14 wherein the shunting comprises shunting around different ones of the different selected rechargeable battery cells at different moments in time during the charging.
20. The system of claim 1 wherein the control circuitry is configured to control an amount of the charging electrical energy applied to one of the rechargeable battery cells using information regarding the temperature of the one rechargeable battery cell.
21. The system of claim 1 wherein the control circuitry is configured to control the one of the shunting devices to shunt different non-zero amounts of the charging electrical energy around one of the respective rechargeable battery cells at different moments in time using information regarding the temperature of the one shunting device.
22. The system of claim 1 wherein the different amounts of the charging electrical energy shunted around different ones of the respective rechargeable battery cells are different non-zero amounts.
23. The system of claim 1 wherein the shunting circuitry is configured to shunt the different amounts of the charging electrical energy around different ones of the rechargeable battery cells at a common moment in time.