Battery system to be deployed in a vehicle having a first battery and a second battery, battery control unit to be deployed in a battery system of a vehicle, and method related to the same

Patent metadata

Field	Value
Publication number	US-11190026-B2
Application number	US-201916436662-A
Country	US
Kind code	B2
Filing date	Jun 10, 2019
Priority date	Sep 30, 2014
Publication date	Nov 30, 2021
Grant date	Nov 30, 2021

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.

First claim

The invention claimed is:

1. A battery system to be deployed in a vehicle, comprising:
a bi-stable relay configured to be electrically coupled between a first battery of the battery system and an electrical system of the vehicle, wherein the first battery comprises a first battery chemistry that has a higher coulombic efficiency than a second battery chemistry of a second battery in the battery system;
a battery control unit communicatively coupled to the bi-stable relay, wherein the battery control unit is configured to:
determine a first voltage of the first battery in the battery system;
determine a second voltage of the second battery in the battery system, wherein the second battery is configured to be electrically coupled to the electrical system of the vehicle;
determine a current key state of the vehicle, wherein the current key state of the vehicle indicates whether the vehicle is currently in a key-on state or a key-off state; and
selectively instruct the bi-stable relay to electrically connect the first battery of the battery system to the electrical system of the vehicle in parallel with the second battery of the battery system based at least in part on the first voltage of the first battery, the second voltage of the second battery, and the current key state of the vehicle, including
instruct the bi-stable relay to electrically disconnect the first battery of the battery system to the electrical system of the vehicle in parallel with the second battery of battery when the first voltage of the first battery is not greater than a threshold voltage to enable the second battery to supply power to the electrical system by itself; and
instruct the bi-stable relay to electrically connect the first battery of the battery system from the electrical system of the vehicle when the first voltage of the first battery in the battery system is greater than the threshold voltage to enable the first battery and the second battery to supply power to the electrical system together; and

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:
the voltage range of the first battery comprises open circuit voltages of the first battery from 0-100% state of charge;
the voltage range of the second battery comprises open circuit voltages of the second battery from 0-100% state of charge; and
a portion of the voltage range of the second battery that overlaps with the voltage range of the first battery corresponds to open circuit voltage of the second battery from 1-74% state of charge.

2. The battery system of claim 1 , wherein, to selectively instruct the bi-stable relay to electrically connect the first battery to the electrical system when the current key state indicates that the vehicle is currently in the key-on state, the battery control unit is configured to:
instruct the bi-stable relay to electrically connect the first battery to the electrical system during regenerative braking when the vehicle is in the key-on state to enable the first battery to capture a majority of power generated during regenerative braking.

3. The battery system of claim 1 , wherein the battery control unit is configured to instruct the bi-stable relay to electrically connect the first battery of the battery system to a starter of the vehicle in parallel with the second battery of the battery system while the vehicle transitions from the key-off state to the key-on state when the second voltage of the second battery is less than the first voltage of the first battery to enable the first battery and the second battery to supply power to the starter together.

4. The battery system of claim 1 , wherein the battery control unit is configured to instruct the bi-stable relay to electrically disconnect the first battery of
the battery system from a starter of the vehicle while the vehicle transitions from the key-off state to the key-on state when the second voltage of the second battery in the battery system is greater than the first voltage of the first battery to enable the second battery to supply power to the starter by itself.

5. The battery system of claim 1 , wherein the battery control unit is configured to selectively instruct the bi-stable relay to electrically connect the first battery of the battery system to the electrical system of the vehicle to maintain the second battery at a full state of charge before regenerative braking to is performed by the vehicle to enable internal resistance of the second battery to steer power generated during the regenerative braking to the first battery.

6. The battery system of claim 1 , wherein the battery control unit is configured to selectively instruct the bi-stable relay to electrically connect the first battery of the battery system to the electrical system of the vehicle to maintain the first battery at less than a full state of charge before regenerative braking is performed by the vehicle to facilitate increasing storage capacity of the battery system available to capture electrical power generated during the regenerative braking.

7. The battery system of claim 1 , wherein:
the first battery chemistry comprises a lithium-ion battery chemistry; and the second battery chemistry comprises a lead-acid battery chemistry.

8. The battery system of claim 1 , wherein the first battery comprises:
an anode implemented at least in part using lithium-titanate; and
a cathode implemented at least in part using a lithium nickel manganese cobalt oxide (NMC) and lithium cobalt oxide (LCO) blend.

9. The battery system of claim 1 , wherein the battery control unit is configured to be communicative coupled to an alternator of the vehicle to enable the battery control unit to:
instruct the alternator to output electrical power with a first alternator voltage higher than a maximum charging voltage of the second battery while the vehicle is performing regenerative braking; and
instruct the alternator to output electrical power with a second alternator voltage less than the first alternator voltage while the vehicle is not performing regenerative braking.

10. A method comprising:
determining, using one or more processors of a battery control unit, a key state of a vehicle, wherein the key state comprises a key-on state and a key-off state;
determining, using one or more processors of the battery control unit, a first voltage of a first battery, wherein the first battery is configured to be coupled to an electrical system, and wherein the first battery comprises a first battery chemistry;
determining, using one or more processors of the battery control unit, a second voltage of a second battery, wherein the second battery comprises a second battery chemistry that has a higher coulombic efficiency than the first battery chemistry;
instructing, using one or more processors of the battery control unit, a bi-stable relay to switch from an open position to a closed position to electrically connect the second battery to the electrical system based at least in part on the first voltage of the first battery, the second voltage of the second battery, and the key state of the vehicle, comprising
instructing the bi-stable relay to switch from the open position to the closed position to electrically connect the second battery from the electrical system in response to determining that the vehicle is in the key-off state and the second voltage of the second battery is greater than a threshold voltage to enable the first battery and the second battery to supply power to the electrical system together;

instructing, using one or more processors of the battery control unit, the bi-s

Assignees

• Cps Tech Holdings Llc

Inventors

• Le Daniel B
• Wyatt Perry M

Classifications

• H02J7/485

  with provisions for charging different types of batteries · CPC title

• H02J7/40

  characterised by the exchange of charge or discharge related data · CPC title

• B60L58/20 Primary

  having different nominal voltages · CPC title

• H02J7/1446

  in response to parameters of a vehicle · CPC title

• B60L2240/547

  Voltage · CPC title