Mode-based disabling of communiction bus of a battery management system
Described herein is a battery system that allows a battery pack to operate in different modes at different times. Each of the different modes may provide its own set of functionality that affects how the battery pack operates and/or reacts to external input signals. A mode may change how the battery pack discharges power by, for example, altering whether terminals are enabled or disabled. A mode may change how the battery pack's hardware operates by, for example, disabling or enabling portions of the battery pack's hardware. A mode may change what battery-related services are provided by the battery pack and available to an end user by, for example, enabling or disabling the sending of battery status information from the battery pack.
1. A battery pack configured to electrically power an end device, the battery pack comprising:
a communication interface circuit configured to interface to a controller area network (CAN) bus;
a controller comprising at least one processor; and
memory storing controller instructions that, when executed by the at least one processor, cause the controller to:
operate the battery pack in a first mode, wherein communication from the battery pack and over the CAN bus is disabled while the battery pack operates in the first mode;
while the battery pack is operating in the first mode, receive a first signal configured to cause the battery pack to enable communication over the CAN bus;
based on the first signal, enable communication from the battery pack and over the CAN bus;
receive, via the communication interface circuit and over the CAN bus, a second signal configured to cause the battery pack to operate in a second mode;
configure the battery pack to operate in the second mode;
operate the battery pack in the second mode, wherein communication from the battery pack and over the CAN bus is enabled while the battery pack operates in the second mode; and
while the battery pack is operating in the second mode, send, via the communication interface circuit and over the CAN bus, one or more messages that include data associated with the battery pack.
2. The battery pack of claim 1 , wherein the battery pack comprises one or more terminals that are configured to, when enabled, transfer electric power from the battery pack to the end device; and
wherein the controller instructions, when executed by the at least one processor, cause the controller to cause, while the battery pack is operating in the first mode, the one or more terminals to be always enabled and always capable of transferring the electric power from the battery pack to the end device.
3. The battery pack of claim 1 , wherein the battery pack comprises one or more terminals that are configured to, when enabled, discharge electric power from the battery pack to the end device;
wherein the battery pack comprises one or more signaling pins that are configured to receive an indicator that indicates the one or more terminals are to be enabled; and
wherein the controller instructions, when executed by the at least one processor, cause the controller to cause, based on receiving the indicator via the one or more signaling pins and while the battery pack is operating in the second mode, the one or more terminals to be enabled and capable of transferring the electric power from the battery pack to the end device.
4. The battery pack of claim 3 , wherein the second mode causes, based on not having received the indicator within a threshold time period, the one or more terminals to be disabled and incapable of transferring the electric power from the battery pack to the end device.
5. The battery pack of claim 1 , wherein the battery pack comprises a power line configured to supply power to the communication interface circuit;
wherein communication from the battery pack and over the CAN bus is enabled if the power line supplies the power to the communication interface circuit; and
wherein the controller instructions, when executed by the at least one processor, cause the controller to prevent, while the battery pack is operating in the first mode, the power line from supplying the power to the communication interface circuit.
6. The battery pack of claim 1 , wherein the first signal comprises a first encryption key received via the communication interface circuit and over the CAN bus;
wherein the second signal comprises a second encryption key received via the communication interface circuit and over the CAN bus; and
wherein the first encryption key is different from the second encryption key.
7. The battery pack of claim 1 , wherein the battery pack comprises a button configured to be pressed by an end user; and
wherein the first signal is received based on the button being pressed.
8. The battery pack of claim 1 , wherein the second mode causes the battery pack to perform one or more of converter balancing, direct balancing, and staggered balancing.
9. The battery pack of claim 1 , wherein the first mode causes the battery pack to implement a first state machine for the first mode;
wherein the second mode causes the battery pack to implement a second state machine for the second mode; and
wherein the controller instructions, when executed by the at least one processor, cause the controller to configure the battery pack to operate in the second mode by initializing the second state machine and causing the battery pack to reset.
10. A method comprising:
configuring a battery pack to operate in a first mode, wherein the battery pack is to electrically power an end device, wherein the battery pack comprises a communication interface circuit configured to interface to a controller area network (CAN) bus, and wherein communication from the battery pack and over the CAN bus is disabled while the battery pack is operating in the first mode;
while the battery pack is operating in the first mode, receiving, by the battery pack, a first signal configured to cause the battery pack to enable communication from the battery pack and over the CAN bus;
based on the first signal, enabling, by the battery pack, communication from the battery pack and over the CAN bus;
receiving, by the battery pack, via the communication interface circuit and over the CAN bus, a second signal configured to cause the battery pack to operate in a second mode;
configuring the battery pack to operate in the second mode;
operating the battery pack in the second mode, wherein communication from the battery pack and over the CAN bus is enabled while the battery pack operates in the second mode; and
while the battery pack is operating in the second mode, sending, by the battery pack, via the communication interface circuit and over the CAN bus, one or more messages that include data associated with the battery pack.
11. The method of claim 10 , wherein the battery pack comprises one or more terminals that are configured to, when enabled, transfer electric power from the battery pack to the end device; and
wherein the method further comprises causing, while the battery pack is operating in the first mode, the one or more terminals to be always enabled and always capable of transferring the electric power from the battery pack to the end device.
12. The method of claim 10 , wherein the battery pack comprises one or more terminals that are configured to, when enabled, transfer electric power from the battery pack to the end device;
wherein the battery pack comprises one or more signaling pins that are configured to receive an indicator that indicates the one or more terminals are to be enabled;
wherein the method further comprises causing, based on receiving the indicator via the one or more signaling pins and while the battery pack is operating in the second mode, the one or more terminals to be enabled and capable of transferring the electric power from the battery pack to the end device.
13. The method of claim 12 , further comprising causing, based on not having received the indicator within a threshold time period and while the battery pack is operating in the second mode, the one or more terminals to be disabled and incapable of transferring the electric power from the battery pack to the end device.
14. The method of claim 10 , wherein the battery pack comprises a power line configured to supply power to the communication interface circuit;
wherein communication from the battery pack and over the CAN bus is enabled if the power line supplies the power to the communication interface circuit; and
wherein the method further comprises preventing, while operating in the first mode, the power line from supplying the power to the communication interface circuitry.
15. The method of claim 10 , wherein the first signal comprises a first encryption key received via the communication interface circuitry and over the CAN bus;
wherein the second signal comprises a second encryption key received via the communication interface circuit and over the CAN bus; and
wherein the first encryption key is different from the second encryption key.
16. The method of claim 10 , wherein the battery pack comprises a button configured to be pressed by an end user; and
wherein receiving the first signal is performed based on the button being pressed.
17. The method of claim 10 , wherein the second signal comprises an encryption key.
18. The method of claim 10 , wherein the first mode causes the battery pack to implement a first state machine for the first mode;
wherein the second mode causes the battery pack to implement a second state machine for the second mode; and
wherein configuring the battery pack to operate in the second mode is performed by initializing the second state machine and causing the battery pack to reset.
19. A method comprising:
While a battery pack is operating in the first mode, sending, by a computing device and to the battery pack, a first signal configured to cause the battery pack to enable communication from the battery pack and over a controller area network (CAN) bus, wherein communication from the battery pack and over the CAN bus is disabled while the battery pack is operating in the first mode;
sending, by the computing device and to the battery pack over the CAN bus, a second signal configured to cause the battery pack to operate in a second mode, wherein communication from the battery pack and over the CAN bus is enabled while the battery pack operates in the second mode; and
while the battery pack is operating in the second mode, receiving, by the computing device and from battery pack over the CAN bus, one or more messages that include data associated with the battery pack.
20. The method of claim 19 , wherein the first signal comprises a first encryption key;
wherein the second signal comprises a second encryption key received via the communication interface circuit and over the CAN bus; and
wherein the first encryption key is different from the second encryption key.