Multi-cell battery management device
Multi-cell battery management devices, systems, and method of operation are disclosed herein. A multi-cell battery pack includes a power output terminal and a plurality of battery cells each having a positive terminal and a negative terminal connected in series. Each cell of the plurality of battery cells includes: i) a cell control processor to monitor cell voltage, cell current, cell temperature, and cell fuse status; ii) a programmable cell balance shunt controlled by the cell control processor that varies the internal resistance of each cell of the plurality of battery cells; and iii) a data communications circuit connected to the cell control processor and to the positive terminal and the negative terminal of each cell, the communications circuit enabling data communications over the positive terminal and the negative terminal of each cell, and wherein the cell control processor responds to commands received via the data communications circuit to vary an operating state of the programmable cell balance shunt.
1. A multi-cell battery management device, the device comprising:
a battery pack including a power output terminal and a plurality of battery cells each having a positive and a negative terminal and connected in series fashion, and wherein each of the plurality of battery cells comprises:
a) a cell control processor that monitors cell voltage, cell current, cell temperature and cell fuse status;
b) a programmable cell balance shunt controlled by the cell control processor that varies internal resistance of each of the battery cells; and
c) a data communications circuit connected to the cell control processor and to the positive and negative terminals of each cell, the communications circuit enabling data communications over the each of the positive terminal and the negative terminal of each cell of the plurality of battery cell positive and negative output terminals, and wherein the cell control processor responds to commands received via the data communications circuit to vary the operating state of the programmable shunt.
2. The multi-cell battery management device of claim 1 , wherein the multi-cell battery management device further comprises a micro-processor based controller or microcontroller (MCU) that executes a computer program to monitor and control battery passive cell balancing and a control switch via a control signal.
3. The multi-cell battery management device of claim 2 , wherein the controller transmits shunt control data or voltage control data to micro-controllers within the battery cells, wherein the battery cells respond by turning on or off the resistance of cell balance shunts to adjust the operating condition of their respective battery cells and achieve cell balancing or a desired cell output voltage.
4. The multi-cell battery management device of claim 2 , wherein the controller operates to direct micro-processor controllers within the battery cells to enable or disable cell balance shunts within the battery cells to achieve a desired cell voltage.
5. The multi-cell battery management device of claim 2 , wherein the controller communicates precise cell balance shunt settings to micro-processor controllers within the battery cells to achieve voltage balancing.
6. The multi-cell battery management device of claim 1 , wherein the multi-cell battery management device operates to reduce higher cell voltages to match those of the lower voltage cells in the battery pack to prevent damage.
7. The multi-cell battery management device of claim 1 , wherein the programmable cell balance shunt further comprises circuit components used to control cell output voltage by varying resistance of the cell balance shunt.
8. The multi-cell battery management device of claim 1 , wherein the programmable cell balance shunt controlled by the cell control processor varies internal resistance of each of the plurality of battery cells individually.
9. The multi-cell battery management device of claim 1 , wherein the programmable cell balance shunt has low resistance to prevent significant loss of power via resistive thermal heating.
10. The multi-cell battery management device of claim 1 , wherein each of the plurality of battery cells further comprises unique identification when communicating with a micro-processor based controller or microcontroller (MCU).
11. A method of operating a battery management system processor to achieve voltage balancing, wherein the battery management system processor comprises a data communications circuit connected to a power output terminal of a battery pack, and wherein the battery management processor performs the following steps:
i) obtaining cell voltage, cell current, cell temperature and cell fuse status data for each of a plurality of battery cells by transmitting and receiving via the data communications circuit,
ii) determining desired cell output voltages based on the cell voltage, cell current, cell temperature and cell fuse status for each of the plurality of battery cells, and
iii) transmitting desired cell output voltage data to the data communications circuit of each of the plurality of battery cells using the data communications circuit of the battery management system processor.