# US 11,451,071 B2 · Battery electric vehicle energy storage system and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,451,071 B2 - Document ID: US11451071B2 - Status: Granted - Kind: B2 - Application number: 16/890,344 - Filed: 2020-06-02 - Published: 2021-12-02 - Granted: 2022-09-20 - Earliest claimed: 2020-06-02 - Assignees: GM Global Technology Operations LLC - Applicants: GM Global Technology Operations LLC - Inventors: Fang Dai; Shifang Li; Jinming Liu; Yue Fan; Mei Cai - Web page: https://patentgrep.com/patent/US11451071B2 ## CPC - H02J 7/575: {Parallel/serial switching of connection of batteries to charge or load circuit} - B60L 53/62: in response to charging parameters, e.g. current, voltage or electrical charge - B60L 58/19: Switching between serial connection and parallel connection of battery modules - H02J 7/825: {Detection of fully charged condition} - H02J 7/977: {of the battery} - H02J 7/82: Control of state of charge [SOC] - H02J 2105/37: exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] - Y02T 10/7072: Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors - Y02T 90/12: Electric charging stations - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A battery electric vehicle includes a high voltage rechargeable energy storage system (RESS). The RESS includes several battery modules reconfigurable among parallel and series arrangements. During reconfiguration transitions, a low voltage battery services low voltage loads of the battery electric vehicle. The low voltage battery is preconditioned in advance of reconfigurations. ## Claims ### Claim 1 A method for reconfiguring a high voltage (HV) rechargeable energy storage system (RESS) having a plurality of HV DC battery modules, a HV bus and an auxiliary power module (APM) selectively couplable between HV DC battery modules and a low voltage (LV) DC auxiliary battery of a LV RESS, comprising: prior to a reconfiguration of the HV RESS, preconditioning the LV DC auxiliary battery to a predetermined state of discharge readiness sufficient to solely service LV electrical loads on a LV bus, comprising establishing at least one predetermined battery parameter to a respective target; isolating with the APM the LV RESS and the LV bus from the HV RESS and the HV bus during a reconfiguration of the HV RESS; and electrically servicing the LV electrical loads on the LV bus with the LV DC auxiliary battery during the reconfiguration of the HV RESS. ### Claim 2 (depends on 1) The method of claim 1, wherein reconfiguration of the HV RESS comprises establishing a series arrangement of HV DC battery modules. ### Claim 3 (depends on 1) The method of claim 1, wherein reconfiguration of the HV RESS comprises establishing a parallel arrangement of HV DC battery modules. ### Claim 4 (depends on 1) The method of claim 1, wherein reconfiguration of the HV RESS comprises isolating the LV DC auxiliary battery from one of the HV DC battery modules and subsequently coupling the LV DC auxiliary battery to another of the HV DC battery modules. ### Claim 5 (depends on 1) The method of claim 1, wherein the at least one predetermined battery parameter comprises battery temperature. ### Claim 6 (depends on 1) The method of claim 1, wherein the at least one predetermined battery parameter comprises battery state of charge. ### Claim 7 (depends on 1) The method of claim 1, wherein preconditioning the LV DC auxiliary battery comprises running current through the LV DC auxiliary battery. ### Claim 8 A method for operating an energy storage system having a plurality of high voltage (HV) DC battery modules and an auxiliary power module (APM) selectively couplable between HV DC battery modules and a low voltage (LV) DC auxiliary battery, comprising: executing a direct current recharge routine for a rechargeable battery energy storage system, the recharge routine comprising selectively reconfiguring the rechargeable battery energy storage system from among a plurality of configurations during the recharge routine; in advance of an incipient reconfiguration of the rechargeable battery energy storage system, flowing current through the LV DC auxiliary battery to establish a predetermined state of discharge readiness of the LV DC auxiliary battery; and during any reconfiguration of the rechargeable battery energy storage system, isolating with the APM the LV DC auxiliary battery from all HV DC battery modules and electrically servicing a predetermined electrical load with the LV DC auxiliary battery. ### Claim 9 (depends on 8) The method of claim 8, wherein the plurality of configurations during the recharge routine comprises a series arrangement of HV DC battery modules and a parallel arrangement of HV DC battery modules, and wherein reconfiguring the rechargeable battery energy storage system comprises transitioning from one of the parallel and series arrangements of HV DC battery modules to the other of the parallel and series arrangements of HV DC battery modules. ### Claim 10 (depends on 8) The method of claim 8, wherein the plurality of configurations during the recharge routine comprises a series arrangement of HV DC battery modules and a parallel arrangement of HV DC battery modules, and wherein reconfiguring the rechargeable battery energy storage system comprises decoupling the LV DC auxiliary battery from one of the HV DC battery modules to another of the HV DC battery modules while the HV DC battery modules remain in the series arrangement. ### Claim 11 (depends on 8) The method of claim 8, wherein flowing current through a LV DC auxiliary battery to establish a predetermined state of discharge readiness of the LV DC auxiliary battery comprises alternating between charge and discharge current through the LV DC auxiliary battery. ### Claim 12 (depends on 11) The method of claim 11, wherein the discharge current through the LV DC auxiliary battery comprises discharge current servicing a vehicle accessory load. ### Claim 13 (depends on 11) The method of claim 11, wherein the discharge current through the LV DC auxiliary battery comprises discharge current servicing at least one of the HV DC battery modules. ### Claim 14 A battery electric vehicle, comprising: a controller; an energy storage system having a plurality of high voltage (HV) DC battery modules and an auxiliary power module (APM) selectively couplable between HV DC battery modules and a low voltage (LV) DC auxiliary battery; the controller configured to: execute a direct current recharge routine for a rechargeable battery energy storage system, the recharge routine comprising selectively reconfiguring the rechargeable battery energy storage system from among a plurality of configurations during the recharge routine; in advance of an incipient reconfiguration of the rechargeable battery energy storage system, flow current through the LV DC auxiliary battery to establish a predetermined state of discharge readiness of the LV DC auxiliary battery; and during any reconfiguration of the rechargeable battery energy storage system, isolate with the APM the LV DC auxiliary battery from all HV DC battery modules and electrically service a predetermined electrical load with the LV DC auxiliary battery. ### Claim 15 (depends on 14) The battery electric vehicle of claim 14, wherein the controller configured to flow current through the LV DC auxiliary battery to establish a predetermined state of discharge readiness of the LV DC auxiliary battery comprises alternating between charge and discharge current through the rechargeable LV DC auxiliary battery. ### Claim 16 (depends on 15) The battery electric vehicle of claim 15, wherein alternating between charge and discharge current through the LV DC auxiliary battery comprises discharge current through the LV DC auxiliary battery servicing a vehicle accessory load. ### Claim 17 (depends on 15) The battery electric vehicle of claim 15, wherein alternating between charge and discharge current through the LV DC auxiliary battery comprises discharge current through the LV DC auxiliary battery servicing at least one of the HV DC battery modules. ### Claim 18 (depends on 14) The battery electric vehicle of claim 14, wherein selectively reconfiguring the rechargeable battery energy storage system from among a plurality of configurations comprises transitioning from one of parallel and series arrangements of HV DC battery modules to the other of the parallel and series arrangements of HV DC battery modules. ### Claim 19 (depends on 14) The battery electric vehicle of claim 14, wherein selectively reconfiguring the rechargeable battery energy storage system from among a plurality of configurations comprises decoupling the LV DC auxiliary battery from one of the HV DC battery modules to another of the HV DC battery modules while the HV DC battery modules remain in a series arrangement.