Battery management system and method for transferring data within the battery management system

A battery management system is provided. The system includes a battery monitoring device having a microprocessor and a hardware component. The microprocessor identifies a non-modifiable node ID from the hardware component. The microprocessor also obtains operational parameters associated with the at least one battery cell. The microprocessor computes a network ID for the battery monitoring device based on the non-modifiable node ID. The system further includes a main controller that communicates with the battery monitoring device via a communication bus utilizing the network ID.

BACKGROUND

Battery systems typically have components that monitor a voltage of a battery cell. However, when the components are in a distributed network, typically DIP switches have been utilized to select addresses of the components. However, an inherent problem with the foregoing technique for selecting an address of a component is that a person may inadvertently select an incorrect address, or select an address that is already assigned to another component. Further, the DIP switch can become degraded or damaged which could result in an incorrect address being utilized by a component.

Accordingly, the inventors herein have recognized a need for an improved battery management system.

SUMMARY

A method for transferring data within a battery management system in accordance with an exemplary embodiment is provided. The battery management system has a battery monitoring device, a communication bus, and a main controller. The method includes identifying a non-modifiable node ID associated with the battery monitoring device from a hardware component of the battery monitoring device, utilizing a microprocessor of the battery monitoring device. The method further includes computing a network ID for the battery monitoring device based on the non-modifiable node ID, utilizing the microprocessor. The method further includes measuring operational parameters associated with at least one battery cell, utilizing the battery monitoring device. The method further includes transmitting data corresponding to the measured operational parameters from the microprocessor through the communication bus to the main controller, utilizing the network ID.

A battery management system in accordance with another exemplary embodiment is provided. The battery management system includes a battery monitoring device having a microprocessor and a hardware component. The microprocessor is configured to identify a non-modifiable node ID from the hardware component. The microprocessor is further configured to obtain operational parameters associated with the at least one battery cell. The microprocessor is further configured to compute a network ID for the battery monitoring device based on the non-modifiable node ID. The battery management system further includes a main controller configured to communicate with the battery monitoring device via a communication bus.

DETAILED DESCRIPTION

Referring to theFIG. 1, a block diagram of a battery management system10for monitoring battery cells and controlling operation of the battery cells in accordance with an exemplary embodiment is provided. The battery management system10includes a main controller20, a memory device22, battery monitoring devices24,26, a communication bus28, and battery cells30,32,34,36. An advantage of the battery management system10is that the battery monitoring devices24,26can each self assign a non-modifiable node ID and network ID for communicating through the communication bus28with the main controller20.

The term “non-modifiable node ID” means a node identifier associated with a battery monitoring device that is set at the time of manufacture of the battery monitoring device and cannot be changed thereafter. The term “network ID” is an identifier associated with a device communicating over a communication bus.

The main controller20is provided to receive data corresponding to measured operational parameters associated with the battery cells30,32,34,36from the battery monitoring devices24,26for monitoring the battery cells and controlling operation of the battery cells. The main controller20is operably coupled to a memory device22that can store data corresponding to the received operational parameters and other data and software routines. The main controller20is further operably coupled to the communication bus28for communicating with the battery monitoring devices24,26. In one exemplary embodiment, the main controller20is implemented utilizing a computer or a microprocessor.

Referring toFIGS. 1 and 2, the main controller20is configured to access a table200in the memory device22that identifies the battery monitoring devices operably coupled to the communication bus28. In one exemplary embodiment, the table200includes three columns: Device No., Node ID, Enabled Map, and Description. Further, the table200includes 12 rows corresponding to 12 different battery monitoring devices. For purposes of simplicity, only two battery monitoring devices24,26will be discussed in the illustrated embodiment ofFIG. 1. Each Node ID value (i.e., node ID) in the table200is a distinct value identifying a specific battery monitoring device. Each Device Number (No.) is a distinct value indicating an ordinal or position of a node ID in the table200. Each Enabled Map value is a value indicating whether a specific battery monitoring device output is enabled or disabled. In other words, the Enabled Map values allows the main controller20to determine which outputs of a battery monitoring device are actually connected and will be reporting an appropriate measured parameter. The Enabled Map allows for increased flexibility for packaging of battery modules containing numerous battery cells since each battery monitoring device can be manufactured to disable particular outputs that become inaccessible due to battery shape and/or configuration. Further, each Description in the table200is a binary value indicating whether specific battery cell voltages and temperatures will be measured by a specific battery monitoring device. In one exemplary embodiment, each battery monitoring device is capable of measuring and reporting 10 battery cell voltages and four temperatures per battery module containing the battery cells.

The communication bus28routes data bi-directionally between the main controller20and the battery monitoring devices24,26. Of course, in alternative embodiments, additional battery monitoring devices could be operably coupled to the communication bus28. In one exemplary embodiment, the communication bus28is a CAN bus. Of course, in alternative embodiments, other types of communication buses known to those skilled the art could be utilized.

The battery monitoring device24is provided to measure operational parameters associated with the battery cells30,32and to transmit data corresponding to the measured operational parameters to the main controller20via the communication bus28. The battery monitoring device44includes a hardware component60, voltage sensors62,64, a temperature sensor66, a microprocessor68, and a memory device70.

The hardware component60has non-modifiable node ID information stored therein. In one exemplary embodiment, the hardware component60is a set of resistors coupled to the microprocessor68and some of which are further coupled to electrical ground. The microprocessor68can sample voltages across the resistors to determine a binary value corresponding to the non-modifiable node ID associated with the battery monitoring device24. In another exemplary embodiment, the hardware component60is a non-volatile memory device that has the non-modifiable node ID stored therein. The microprocessor68can read the non-volatile memory device to retrieve the node ID associated with the device24. Of course, in alternative embodiments, other types of devices known to those skilled in the art could be utilized to set the non-modifiable node ID associated with the device24.

The voltage sensors62,64are provided to measure the output voltages of the battery cells30,32, respectively. The voltage sensors62,64transmit signals to the microprocessor68indicative of the measured output voltages of the battery cells30,32, respectively.

The temperature sensor66is provided to measure a temperature level associated with the battery cells30,32. The temperature sensor66transmits a signal to the microprocessor68indicative of a measured temperature level of the battery cells30,32, respectively.

The battery cells30,32are electrically coupled to the voltage sensors62,64, respectively. In one exemplary embodiment, the battery cells30,32are pouch type lithium-ion battery cells. Of course, in alternative embodiments, the battery cells30,32could be any type of battery cell known to those skilled in the art.

The microprocessor68is operably coupled to the hardware component60, the voltage sensors62,64, the temperature sensor66, and the memory device70. As discussed above, the microprocessor68can sample or read the hardware component60to determine a node ID associated with the battery monitoring device24. Further, the microprocessor68is configured to determine a network ID associated with the device24based on the node ID to allow bi-directional communication between the device24and the main controller20via the communication bus28. In one exemplary embodiment, each node ID is an 8-bit or 1 byte number. Further, in one exemplary embodiment, the bus28is a controller-area network (“CAN”) bus and each network ID associated with a battery monitoring device is a CAN ID. A standard CAN ID is 11 bits in size. A unique starting CAN ID can be computed for each battery monitoring device by performing an arithmetic shift of a respective node ID to the left by three significant digits to obtain a unique 11-bit number. Further, referring toFIG. 3, an advantage obtained by utilizing the foregoing method for determining the CAN ID is that there is an exclusive range of 8 unique CAN IDs that can be used for each battery monitoring device between two consecutive battery monitoring devices.

It should be noted that a copy of the table200is also stored in the memory device70and is accessed by the microprocessor68. The microprocessor68determines a device number (designated as Device No. in the table200) associated with the battery monitoring device24utilizing the determined node ID and the table200. It should be noted that in one exemplary embodiment, the main controller20to sends commands having a device number to the battery monitoring devices on the communication bus28and the battery monitoring device associated with the specific device number performs tasks in response to the command. For example, the microprocessor68can receive a command from the main controller20which requests measured operational parameters (e.g., voltage levels and a temperature level) associated with the battery cells30,32. In response to the command, the battery monitoring device24measures the operational parameters and transmits data corresponding to the operational parameters to the main controller20.

The battery monitoring device26is provided to measure operational parameters associated with the battery cells34,36and to transmit data corresponding to the measured operational parameters to the main controller20via the communication bus28. The battery monitoring device46includes a hardware component160, voltage sensors162,164, a temperature sensor166, a microprocessor168, and a memory device170. The battery monitoring device26operates in a substantially similar manner as the battery monitoring device24, except that the battery monitoring device26measures the operational parameters associated with the battery cells34,36and reports the associated operational parameters to the main controller20. Further, the battery monitoring device46utilizes a distinct device number, node ID and network ID associated with the battery monitoring device46, for bi-directional to communication with the main controller20.

Referring toFIG. 4, a flowchart of a method for transferring data within the battery management system10will be described. Also, for purposes of simplicity, the following method will be discussed with respect to the battery monitoring device24.

At step250, the microprocessor68of the battery monitoring device24determines the non-modifiable node ID associated with the battery monitoring device24by sampling or reading the hardware component60.

At step252, the microprocessor68determines a network ID associated with the battery monitoring device24based on the node ID associated with the device24.

At step254, the microprocessor68determines an ordinal position of the node ID associated with the device24in the table200that lists the node IDs of the battery monitoring devices coupled to the communication bus28. In other words, the microprocessor68determines the device number associated with the device24.

At step256, the microprocessor68listens for a command sent to the battery monitoring device24from the main controller20via the communication bus28.

At step258, the microprocessor68processes a command sent to the battery monitoring device24by the main controller20. For example, the microprocessor68can receive a command from the main controller20which requests measured operational parameters (e.g., voltage levels and a temperature level) associated with the battery cells30,32. In response to the command, the battery monitoring device24measures the operational parameters and transmits data corresponding to the measured operational parameters to the main controller20.

At step260, the microprocessor68broadcasts the result of the processed command to the main controller20using the network ID associated with the battery monitoring device24. In other words, the microprocessor68transmits data corresponding to the measured operational parameters to the main controller20via the communication bus20.

At step262, the microprocessor68makes a determination as to whether a shutdown command was received from the main controller20. If so, the microprocessor68shuts down the battery monitoring device24. If not, the method returns to the step256.