EVE Battery Performance and Durability subgroup report

WLTP Subgroup on Electric Vehicles: Status of Phase 2 effort

Updated information document from the Method of Stating Energy Consumption subgroup.

Summary of discussions with experts from WLTP-SG-EV, SAE, ISO, and KATRI.

Under the auspices of the US EPA, FEV North America, Inc. conducted an extensive literature review on the subject of EV battery durability for the EVE Informal Working Group. The review examines the electrochemical basis for the deterioration of batteries used in BEV, HEV, and PHEV applications along with testing activities performed on such electrified vehicles and automotive grade cells, battery packs, etc.

Presentation concerning an electric bus fire in 2009 reported by a Chinese research institute.

Presentation on fire resistance testing using gasoline instead of propane.

Proposal based on SAE test procedures for drop testing and rotation (rollover) testing.

China positions on the justification and development of thermal propagation testing.

Proposed text for a sequential testing program to test the Battery Management System (BMS) response at the safety boundary limits of the REESS during operation. The test evaluates the ability of the vehicle’s BMS to safely monitor and control the REESS under external inputs such that there is no damage to the REESS and no hazardous conditions arise.

Task force chairman’s review of the current text and action items.

NHTSA note proposing that the specific battery SOC measurement procedure be determined by manufacturer in accordance with the battery design.

EVS TF5 draft text as agreed to date for a test procedure to assess the performance of the REESS in the event of thermal runaway by a single cell. The intent is to safeguard against thermal propagation that could result in a system fire or explosion.

Proposal for the final draft REESS pass/fail requirements under test procedures for assessing risks associated with electrolyte leakage and gas venting, for incorporation into the proposed electric vehicle safety GTR.

Proposal to include in the testing of REESS physical integrity such vehicle structural elements as may have an impact on test results. In other words, the manufacturer may request protective body elements to be included in the test set up.

The isolation monitoring system monitors the isolation resistance of the vehicle system periodically or continuously and warns if isolation loss is detected. Japan proposes this requirement in order to signal problems with isolation so the vehicle can be brought in for service before the failure reaches higher severity where the occupant could receive an electrical shock.

OICA proposals for battery management system testing.

OICA argument for delaying the establishment of water testing until the “phase 2” development of the electric vehicle safety test cycle.

OICA proposals for test procedures for thermal propagation.