Cost effective configuration for supercapacitors for HEV

1. A rechargeable energy storage system (RESS) for a hybrid electric vehicle comprising:

a power supply module that includes at least one battery; and

a startup module that includes:

N supercapacitors, wherein each of the N supercapacitors is arranged in parallel with others of the N supercapacitors and with the at least one battery, and wherein N is an integer greater than one; and

an adjustable power supply arranged in series with at least one of the N supercapacitors and in parallel with the at least one battery,

wherein the adjustable power supply maintains a voltage across the N supercapacitors below a predetermined voltage.

2. The RESS of claim 1 further comprising a regulator control module that monitors the voltage across the N supercapacitors and selectively adjusts the voltage based on a comparison between the voltage and the predetermined voltage.

3. A system comprising the RESS of claim 1 and further comprising:

a motor control module arranged at least one of in series and in parallel with the N supercapacitors.

4. The system of claim 3 wherein the N supercapacitors provide current to the motor control module during at least one of a startup period and normal operation of the hybrid electric vehicle.

5. The RESS of claim 1 wherein the N supercapacitors are charged during at least one of regenerative breaking, normal deceleration, and acceleration of the hybrid electric vehicle.

6. The RESS of claim 1 wherein a voltage of the adjustable power supply is less than or equal to a predetermined threshold voltage for the N supercapacitors.

7. The RESS of claim 1 further comprising at least one supercapacitor connected in series with at least one of the N supercapacitors.

8. A rechargeable energy storage method for a hybrid electric vehicle comprising:

providing at least one battery;

arranging each of N supercapacitors in parallel with the at least one battery, wherein N is an integer greater than or equal to one; and

arranging an adjustable power supply in series with at least one of the N supercapacitors and in parallel with the at least one battery, wherein the adjustable power supply maintains a voltage across the N supercapacitors below a predetermined voltage.

9. The method of claim 8 further comprising:

monitoring the voltage across the N supercapacitors using a regulator control module; and

selectively adjusting the voltage based on a comparison between the voltage and the predetermined voltage.

10. The method of claim 8 and further comprising:

arranging a motor control module in parallel with the N supercapacitors.

11. The method of claim 10 wherein the N supercapacitors provide current to the motor control module during at least one of a startup period and normal operation of the hybrid electric vehicle.

12. The method of claim 8 wherein the N supercapacitors are charged during at least one of regenerative breaking, normal deceleration, and acceleration of the hybrid electric vehicle.

13. The method of claim 8 wherein a voltage of the adjustable power supply is less than or equal to a predetermined threshold voltage for the N supercapacitors.

14. The method of claim 8 wherein at least one supercapacitor is connected in series with at least one of the N supercapacitors.

15. A system for a hybrid electric vehicle, the system comprising:

a battery system that includes a plurality of batteries connected in series, the battery system being configured to output a current for powering an electric motor of the hybrid electric vehicle, wherein the electric motor is configured to propel the hybrid electric vehicle;

a supercapacitor system that includes a plurality of supercapacitors connected in parallel, the supercapacitor system being connected in parallel to the battery system and being configured to output additional current for powering the electric motor of the hybrid electric vehicle when a current requested by the electric motor is greater than the current being output by the battery system; and

an adjustable switching regulator connected between the battery system and the supercapacitor system, the adjustable switching regulator being configured to maintain a voltage across the supercapacitor system at less than or equal to a predetermined voltage threshold and to enable recharging of the supercapacitor system.

16. The system of claim 15 , wherein a reference terminal of the adjustable switching regulator is connected to a negative terminal of the battery system, wherein an input terminal of the adjustable switching regulator is connected to a positive terminal of the battery system, and wherein an output terminal of the adjustable switching regulator is connected to a reference node of the supercapacitor system.

17. The system of claim 16 , wherein the adjustable switching regulator is configured to enable recharging of the supercapacitor system during at least one of vehicle deceleration and regenerative braking by decreasing the voltage across the supercapacitor system.

18. The system of claim 17 , wherein the adjustable switching regulator is configured to enable recharging of the supercapacitor system during at least one of vehicle deceleration and regenerative braking by decreasing the voltage across the supercapacitor system to a voltage less than a voltage at the positive terminal of the battery system.

19. The system of claim 15 , wherein each of the plurality of supercapacitors includes a porous material that increases an active electrode surface area of each of the plurality of supercapacitors.

20. The system of claim 15 , wherein recharging of the battery system is enabled during steady-state vehicle operation, and wherein an internal combustion engine of the hybrid electric vehicle is configured to propel the hybrid electric vehicle during the steady-state vehicle operation.