BATTERY SYSTEM BI-STABLE RELAY CONTROL

• US 20160089992A1
• Filed: 09/30/2014
• Published: 03/31/2016
• Est. Priority Date: 09/30/2014
• Status: Active Grant

• Current Assignee: CPS Technology Holdings, LLC
• Original Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Inventors: Le, Daniel B., Wyatt, Perry M.
• Granted Patent: US 10,320,202 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: H02J 7/00032 characterised by data exchange
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: H02J 7/1446 in response to parameters of a vehicle
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

A 12 volt automotive battery system includes a first battery coupled to an electrical system, and the first battery includes a first battery chemistry. Further, the 12 volt automotive battery system includes a second battery coupled in parallel with the first battery and selectively coupled to the electrical system via a bi-stable relay. The second battery includes a second battery chemistry that has a higher coulombic efficiency than the first battery chemistry. Additionally, the bi-stable relay couples the second battery to the electrical system during regenerative braking to enable the second battery to capture a majority of the power generated during regenerative braking. Furthermore, the bi-stable relay maintains a coupling of the second battery to the electrical system when the vehicle transitions from a key-on position to a key-off position.

Claims

1. A battery system, comprising:

a first battery configured to be coupled to an electrical system, wherein the first battery comprises a first battery chemistry;

a second battery coupled in parallel with the first battery and configured to be selectively coupled to the electrical system via a bi-stable relay, wherein the second battery comprises a second battery chemistry that has a higher coulombic efficiency than the first battery chemistry, and the bi-stable relay is configured to couple the second battery to the electrical system during regenerative braking to enable the second battery to capture a majority of power generated during regenerative braking, and the bi-stable relay is configured to maintain a coupling of the second battery to the electrical system when a vehicle transitions from a key-on position to a key-off position.

2. The battery system of claim 1, comprising an alternator configured to output a first voltage during regenerative braking to charge the second battery and to output a second voltage otherwise, wherein the first voltage is higher than the second voltage.

3. The battery system of claim 1, wherein the bi-stable relay is configured to couple the second battery to the electrical system when the vehicle transitions from a long key-off position to the key-on position and a first voltage of the first battery is less than a second voltage of the second battery.

4. The battery system of claim 1, wherein the bi-stable relay is configured to maintain the second battery decoupled from the electrical system when the vehicle transitions from a long key-off position to the key-on position and a first voltage of the first battery is greater than a second voltage of the second battery.

5. The battery system of claim 1, wherein the bi-stable relay maintains the coupling of the second battery to the electrical system for a predetermined amount of time after the vehicle transitions from the key-on position to the key-off position.

6. The battery system of claim 1, comprising a battery control unit configured to maintain the first battery generally at a full state of charge before regenerative braking to enable the first battery to steer power generated during regenerative braking to the second battery using an internal resistance of the first battery.

7. The battery system of claim 1, comprising a battery control unit configured to maintain the first battery at a less than a full state of charge before regenerative braking to increase storage capacity of the second battery.

8. The battery system of claim 1, comprising a housing to house the first battery, the second battery, and the bi-stable relay, wherein the housing comprises a positive terminal and a ground terminal coupled to the first battery and selectively coupled to the second battery via the bi-stable relay, wherein the positive terminal and the ground terminal are configured to couple to the electrical system.

9. The battery system of claim 1, wherein the first battery and the second battery are non-voltage matched such that a voltage range of the second battery is higher than a voltage range of the first battery and do not overlap, wherein the voltage range of the first battery comprises open circuit voltages of the first battery between 0-100% state of charge and the voltage range of the second battery comprises open circuit voltages of the second battery between 0-100% state of charge.

10. The battery system of claim 1, wherein the first battery and the second battery are partial voltage matched such that a voltage range of the first battery and a voltage range of the second battery partially overlap, wherein voltage overlap corresponds to between 1-74% of the second battery'"'"'s total state of charge range, and the voltage range of the first battery comprises open circuit voltages of the first battery between 0-100% state of charge and the voltage range of the second battery comprises open circuit voltages of the second battery between 0-100% state of charge.

11. The battery system of claim 1, wherein the first battery chemistry is lead-acid and the second battery chemistry is lithium ion.

12. The battery system of claim 11, wherein the second battery chemistry is lithium-titanate at the anode and a lithium nickel manganese cobalt oxide (NMC) and lithium cobalt oxide (LCO) blend at the cathode.

13. An automotive battery system, comprising:

a first battery configured to be coupled to an electrical system, wherein the first battery comprises a first battery chemistry;

a second battery coupled in parallel with the first battery and configured to be selectively coupled to the electrical system via a bi-stable relay, wherein the second battery comprises a second battery chemistry that has a higher coulombic efficiency than the first battery chemistry, and the bi-stable relay is configured to couple the second battery to the electrical system during regenerative braking to enable the second battery to capture a majority of power generated during regenerative braking, and the bi-stable relay is configured to maintain the second battery decoupled from the electrical system while starting an engine when a first voltage of the first battery is greater than a second voltage of the second battery.

14. The automotive battery system of claim 13, wherein the bi-stable relay is configured to couple the second battery to the electrical system while starting the engine when the second voltage of the second battery is greater than the first voltage of the first battery.

15. The automotive battery system of claim 13, wherein the bi-stable relay is configured to couple the second battery to the electrical system while starting the engine when the second voltage of the second battery is below a threshold voltage.

16. The automotive battery system of claim 15, wherein the bi-stable relay is configured to decouple the second battery from the electrical system after starting the engine and maintain the second battery decoupled from the electrical system until energy is produced via regenerative braking to charge the second battery.

17. The automotive battery system of claim 13, wherein the first battery and the second battery are non-voltage matched such that a voltage range of the second battery is higher than a voltage range of the first battery and the voltage ranges do not overlap, wherein the voltage range of the first battery comprises open circuit voltages of the first battery between 0-100% state of charge and the voltage range of the second battery comprises open circuit voltages of the second battery between 0-100% state of charge.

18. The automotive battery system of claim 13, wherein the first battery and the second battery are partial voltage matched such that a voltage range of the first battery and a voltage range of the second battery partially overlap, wherein voltage overlap corresponds to between 1-74% of the second battery'"'"'s total state of charge range, and the voltage range of the first battery comprises open circuit voltages of the first battery between 0-100% state of charge and the voltage range of the second battery comprises open circuit voltages of the second battery between 0-100% state of charge.

19. A 12 volt automotive battery system, comprising:

a first battery configured to be selectively coupled to an electrical system via a bi-stable relay, wherein the first battery comprises a first battery chemistry; and

a second battery coupled in parallel with the first battery and configured to be coupled to the electrical system, wherein the second battery comprises a second battery chemistry that has a higher coulombic efficiency than the first battery chemistry;

wherein the bi-stable relay is configured to disconnect the first battery during regenerative braking to enable the second battery to be charged at a voltage higher than a maximum charging voltage of the first battery.

20. The battery system of claim 19, wherein the maximum charging voltage of the first battery is lower than a maximum charging voltage of the second battery.

21. The battery system of claim 20, wherein the voltage higher than the maximum charging voltage of the first battery is between 14.8 to 16.8 volts when the first battery chemistry is lead-acid and the second battery chemistry is lithium ion.

22. The battery system of claim 21, wherein the second battery chemistry is lithium-titanate at the anode and a lithium nickel manganese cobalt oxide (NMC) and lithium cobalt oxide (LCO) blend at the cathode.

23. The battery system of claim 19, comprising a housing to house the first battery, the second battery, and the bi-stable relay, wherein the housing comprises a positive terminal and a ground terminal coupled to the second battery and selectively coupled to the first battery via the bi-stable relay, wherein the positive terminal and the ground terminal are configured to couple to the electrical system.

24. The battery system of claim 19, wherein the bi-stable relay is configured to decouple the first battery from the electrical system when a vehicle transitions from a key-on position to a key-off position and couple the first battery to the electrical system when the vehicle transitions from the key-off position to the key-on position.