Temperature controlled parallel balancing
A method of controlling current in a parallel battery systems includes providing at least two parallel connected batteries, each said battery having an internal resistance and dissipating heat while operating; during operation, measuring at least the temperature and current of each individual battery; and providing instructions to a temperature control system having a temperature control module coupled with each said battery for individually cooling each said battery to adjust temperature of at least one battery in order to maintain the current at a target value.
1. A system for control of current in a parallel battery system, comprising:
at least two parallel connected batteries, each said battery having an internal resistance and dissipating heat while charging and/or discharging;
a temperature controller having a temperature control module coupled with each said battery, each temperature control module capable of independent operation for individually controlling the temperature of each said battery; and
a system controller for receiving information from each said battery related to condition and performance of each said battery and for providing an output signal to each temperature control module to independently adjust the temperature of each said battery,
wherein the independent adjustment of the temperature of each said battery is selected to maintain a target current value for each battery and for the entire parallel battery system.
2. The system of claim 1 , wherein the temperature control system is selected from the group consisting of air cooling, liquid cooling, water cooling, thermoelectric cooling, air heating, liquid heating, and thermoelectric heating.
3. The system of claim 1 , wherein the system controller is selected from the group consisting of a microprocessor or a field programmable gate array (FPGA).
4. The system of claim 1 , wherein the system comprises a thermostat.
5. The system of claim 1 , wherein the system controller is selected to receive information selected from the group consisting of voltage, current, temperature and combinations thereof.
6. The system of claim 1 , wherein the system further includes a tool for evaluating a state of the battery system.
7. A method of controlling current in a parallel battery system, comprising:
providing at least two parallel-connected batteries, each said battery having an internal resistance and dissipating heat while operating;
during operation, measuring at least the temperature and current of each individual battery; and
providing instructions to a temperature control system having a temperature control module coupled with each said battery for individually heating or cooling each said battery to adjust the temperature of at least one battery in order to maintain the current at a target value.
8. The method of claim 7 , further comprising comparing the measured values of each said battery against a target value, said target value related to the state and/or performance of each said battery.
9. The method of claim 8 , wherein the state of the battery is selected from the group of energy, ampere hours (AH), state of health (SOH) and state of charge (SOC).
10. The method of claim 7 , wherein increasing dissipation of heat or lowering the temperature of the battery increases the current value for the battery.
11. The method of claim 7 , wherein decreasing the dissipation of heat or raising the temperature of the battery decreases the current value for the battery.
12. The method of claim 7 , wherein the temperature control system controls the AH of each of the parallel batteries to converge to each other.
13. The method of claim 7 , wherein the temperature control system adjusts the current value of each of the batteries to be the same regardless of AH.
14. The method of claim 7 , wherein the temperature control system adjusts the current value for a particular battery to be a ratio of the other batteries' current values depending on what the known capacity of the particular battery is relative to the rest of the batteries within the parallel battery system.
15. The method of claim 7 , wherein the temperature control system adjusts the SOC of each of the batteries to be the same.
16. The method of claim 7 , wherein the temperature control system reduces the charging and discharging of a particular battery within the parallel battery system if the SOH of the particular battery is more dependent on the watt hours (WH) throughput than the other batteries in the parallel battery system.
17. The method of claim 7 , wherein the temperature control system increases the charging and discharging of a particular battery within the parallel battery system if the SOH of the particular battery is less dependent on the watt hours (WH) throughput than the other batteries in the parallel battery system.