SYSTEM AND METHODS FOR BATTERY MANAGEMENT
A battery management system includes several subsystem blocks, an Energy Storage Master Charger unit, and several battery pack systems. The Energy Storage Master may interface with the Vehicle Master Controller by way of CAN or other communication method to an External Charger. Each battery module within a battery pack may include a Local Module Unit which may communicate with a Pack Master. The Pack Master may communicate with and may be controlled by the Energy Storage Master. Thus, there is a processor to monitor groups of battery cells, a second processor to collect further information about the cell groups, and a third module that takes high-level information from each cell group processor to process and pass on to other vehicle controllers or charger controllers. An integrated BMS may enable cell monitoring, temperature monitoring, cell balancing, string current monitoring, and charger control integration.
1 . A battery management system comprising:
a plurality of local module units, wherein each local module unit monitors at least a cell voltage, temperature, humidity and current from a plurality of battery cells;
at least one pack master board for aggregating data from and communicating with the plurality of local module units;
an energy storage master for interfacing with a vehicle master controller; and
an external charger, the external charger in communication with the vehicle master controller;
wherein the pack master board communicates with the energy storage master to command charge transfer between the plurality of battery cells.
2 . The system of claim 1 , wherein the system is for an electric vehicle.
3 . The system of claim 1 , wherein the vehicle master controller interfaces with the external charger through a charging station interface.
4 . The system of claim 2 , wherein a group of battery cells form a battery module, and a group of battery modules form a battery pack, and a pair of battery packs form a string, and a variable number of strings are included in the electric vehicle; and one local module unit monitors each battery module.
5 . The system of claim 1 , wherein the pack master board communicates with the plurality of local module units using a serial peripheral interface bus.
6 . The system of claim 1 , wherein the pack master board communicates with the energy storage master on a controller area network.
7 . The system of claim 6 , wherein the controller area network is ISO 11898.
8 . The system of claim 1 , wherein the pack master board communicates with the energy storage master using a single controller area network bus.
9 . The system of claim 1 , wherein the pack master board monitors die temperature of the plurality of local module units.
10 . The system of claim 1 , wherein the pack master board communicates with the energy storage master to command charge transfer between the plurality of battery cells by buffering energy into a capacitor from the plurality of battery cells and then transferring the buffered energy into a single battery cell selected from the plurality of battery cells by using the local module unit to turn on transistors moving charge into the selected single battery cell.
11 . The system of claim 10 , wherein the transistors are capable of passing more than 3 Amps continuously.
12 . The system of claim 10 , wherein the capacitor is rated for 20 Watts per channel.
13 . The system of claim 1 , wherein a group of battery cells form a battery module and further comprising an isolated DCDC converter connected to the battery module to charge a selected battery cell from the group of battery cells.
14 . The system of claim 1 , wherein each local module unit comprises liquid or fuse indicators.
15 . The system of claim 10 , wherein the local module unit comprises a multi-cell battery stack monitoring microprocessor chip.
16 . A method for efficient battery management for an electric vehicle comprising:
monitoring a cell voltage, temperature, humidity and current from a plurality of battery cells using a plurality of local module units, wherein a group of battery cells form a battery module and a group of battery modules form a battery pack, and a pair of battery packs form a string;
aggregating data from and communicating with the plurality of local module units using at least one pack master board;
communicating information to and from the at least one pack master board to and from an energy storage master;
communicating information to and from the energy storage master to and from a vehicle master controller; and
communicating from the vehicle master control to an external charger,
wherein the pack master board communicates with the energy storage master to command charge transfer between the plurality of battery cells when a voltage imbalance is detected.
17 . The method of claim 16 , further comprising monitoring a state of health of the plurality of battery cells and bypassing a battery cell within a battery pack based on the state of health.
18 . The method of claim 16 , further comprising disconnecting a battery pack if a short is detected by the plurality of local module units.
19 . The method of claim 16 , further comprising disconnecting a string if a current imbalance is detected.
20 . A battery management system for an electric vehicle comprising:
a plurality of primary processor modules to monitor groups of battery cells, wherein each primary processor module monitors at least a cell voltage, temperature, humidity and current of the battery cells;
a plurality of secondary processor module to collect information about the groups of battery cells from the plurality of primary processor modules; and
a tertiary processor module to collect information from the plurality of secondary processor modules to pass along to a vehicle controller or external charger controllers,
wherein the secondary processor modules communicate with the tertiary processor module to command charge transfer between the battery cells.