Controlling electrical access to a lithium battery on a utility vehicle

Patent metadata

Field	Value
Publication number	US-10322688-B2
Application number	US-201615395245-A
Country	US
Kind code	B2
Filing date	Dec 30, 2016
Priority date	Dec 30, 2016
Publication date	Jun 18, 2019
Grant date	Jun 18, 2019

Abstract

A battery management system (BMS) controls lithium battery access on a utility vehicle. The BMS includes a battery interface that couples with a lithium battery, a load interface that couples with a set of loads of the utility vehicle, and control circuitry coupled with the battery interface and the load interface. The control circuitry mechanically disconnects the battery interface from the load interface in response to a sleep event. Additionally, after the battery interface is mechanically disconnected from the load interface, the control circuitry mechanically reconnects the battery interface to the load interface in response to a wakeup event. Furthermore, after the battery interface is mechanically reconnected to the load interface, the control circuitry maintains connection between the battery interface and the load interface to convey power from the lithium battery to the set of loads of the utility vehicle through the battery interface and the load interface.

First claim

What is claimed is:

1. A battery management system that controls lithium battery access on a utility vehicle, the battery management system comprising:
a lithium battery interface configured to couple to a lithium battery;
a power delivery interface configured to couple to a set of loads of the utility vehicle; and
control circuitry coupled with the lithium battery interface and the power delivery interface, the control circuitry being configured to:
mechanically disconnect the lithium battery interface from the power delivery interface in response to a sleep event,
after the lithium battery interface is mechanically disconnected from the power delivery interface, mechanically reconnect the lithium battery interface to the power delivery interface in response to a wakeup event, and
after the lithium battery interface is mechanically reconnected to the power delivery interface, maintain connection between the lithium battery interface and the power delivery interface to convey power from the lithium battery to the set of loads of the utility vehicle through the lithium battery interface and the power delivery interface;

wherein the control circuitry includes:
a contactor having source contacts configured to couple to the lithium battery interface, target contacts configured to couple to the power delivery interface, and an electromagnetic actuator, and
a wakeup circuit coupled with the electromagnetic actuator of the contactor, the wakeup circuit being configured to (i) actuate the electromagnetic actuator to a first position that connects the source contacts to the target contacts in response to the wakeup event, and (ii) release the electromagnetic actuator to a second position that disconnects the source contacts from the target contacts in response to the sleep event, the second position being different from the first position;

wherein the wakeup circuit includes a timer which the wakeup circuit is configured to start in response to the wakeup event; and
wherein the wakeup circuit is further configured to (i) output an actuation signal to the electromagnetic actuator of the contactor once the timer starts and before the timer expires and (ii) terminate output of the actuation signal to the electromagnetic actuator of the contactor in response to expiration of the timer, the electromagnetic actuator being spring biased from the first position toward the second position to separate the source contacts from the target contacts in response to the wakeup circuit terminating output of the actuation signal.

2. A battery management system as in claim 1 wherein the wakeup circuit is further configured to release the electromagnetic actuator to the second position that disconnects the source contacts from the target contacts in response to a low capacity event in which the lithium battery has discharged to a predefined low capacity level.

3. A battery management system as in claim 1 wherein the wakeup circuit is configured to couple to an ignition switch of the utility vehicle; and
wherein the wakeup circuit is constructed and arranged to start the timer in response to receipt of a wakeup signal due to actuation of the ignition switch from an OFF position to an ON position.

4. A battery management system as in claim 3 wherein the wakeup circuit is further configured to couple to a foot pedal of the utility vehicle; and
wherein the wakeup circuit is constructed and arranged to start the timer in response to receipt of a wakeup signal due to mechanical pressing of the foot pedal from a non-deflected position to a deflected position.

5. A battery management system as in claim 4 wherein the wakeup circuit is further configured to couple to the ignition switch and the foot pedal while the ignition switch and the foot pedal are connected in series to prevent the foot pedal from providing a wakeup signal to the wakeup circuit while the ignition switch is in the OFF position.

6. A battery management system as in claim 4 wherein the wakeup circuit is further configured to couple to a maintenance switch of the utility vehicle; and
wherein the wakeup circuit is constructed and arranged to start the timer in response to receipt of a wakeup signal due to actuation of the maintenance switch from an OFF position to an ON position.

7. A battery management system as in claim 6 wherein the wakeup circuit is further configured to couple to the maintenance switch, the ignition switch, and the foot pedal while the maintenance switch, the ignition switch, and the foot pedal are connected in series to prevent the ignition switch and the foot pedal from providing a wakeup signal to the wakeup circuit while the maintenance switch is turned to the OFF position.

8. A battery management system as in claim 1 wherein the timer of the wakeup circuit is constructed and arranged to indicate that a sleep event has occurred when, after the timer is started, a predefined amount of time elapses without the timer being reset.

9. A battery management system as in claim 8 wherein the predefined amount of time is between 10 hours and 14 hours.

10. A battery management system as in claim 1 wherein the set of loads of the utility vehicle includes a motor controller and an electric motor which is coupled with the motor controller;
wherein the motor controller is configured to (i) receive stored power from the lithium battery and enters a powered state when the electromagnetic actuator actuates to the first position that connects the source contacts to the target contacts in response to the wakeup event, and (ii) no longer receive stored power from the lithium battery and transitions from the powered state to an unpowered state when the electromagnetic actuator releases to the second position that disconnects the source contacts from the target contacts in response to the sleep event; and
wherein the motor controller is constructed and arranged to control delivery of stored power from the lithium battery to the motor while the motor controller is in the powered state.

11. A battery management system as in claim 10 wherein the motor controller is further constructed and arranged to control delivery of regenerative power from the motor to the lithium battery while the motor controller is in the powered state.

12. A battery management system as in claim 10 wherein the control circuitry further includes a charge regulation circuit configured to control delivery of external power from an external power source to the lithium battery to recharge the lithium battery; and
wherein the wakeup circuit is constructed and arranged to adjust operation of the charge regulation circuit in response to communication with the motor controller.

13. A battery management system as in claim 12 wherein the motor controller is further constructed and arranged to provide an external power notification message to the wakeup circuit when a user connects the motor controller to an external power source; and
wherein the wakeup circuitry is constructed and arranged to control operation of the charge regulation circuit in response to receipt of the external power notification message provided by the motor controller.

14. A battery management system as in claim 12 wherein the wakeup circuit is further configured to deactivate the charge regulation circuit in response to detection of a full capacity event in which the lithium battery has charged to a predefined full capacity level.

15. A utility vehicle, comprising:
a utility vehicle body;
a lithium battery supported by the utility vehicle body;
a motor supported by the utility vehicle body;
a motor controller coupled

Assignees

• Textron Innovations Inc

Inventors

• Harvey Arthur James
• Padgett Norman R
• Ledden John
• Bradley Robert Charles
• Warden Patrick Dwaine

Classifications

• B60L53/50

  Charging stations characterised by energy-storage or power-generation means · CPC title

• H02J7/933

  the cycle being controlled or terminated in response to electric parameters · CPC title

• H02J7/927

  with introduction of pulses during the charging process · CPC title

• H02J7/585

  Sequential battery discharge in systems with a plurality of batteries · CPC title

• Y02T10/7072

  Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors · CPC title