TO: AC Transit Board of Directors
FROM: Michael A. Hursh, General Manager
SUBJECT: Report on New Flyer Fuel Cell Bus A123 Battery Failures
BRIEFING ITEM
RECOMMENDED ACTION(S):
Title
Consider receiving a report on the New Flyer fuel cell bus A123 battery failures, investigation, and conclusion.
Body
STRATEGIC IMPORTANCE:
Goal - Convenient and Reliable Service
Initiative - Zero Emission Programs
This report provides a summary of the results from the high voltage battery system diagnostics performed by the manufacturer on three New Flyer fuel cell buses and corrective actions implemented.
BUDGETARY/FISCAL IMPACT:
There are no budgetary or fiscal impacts directly related to this report.
BACKGROUND/RATIONALE:
Since January 2020, the District has been operating ten 2018 New Flyer 40-foot fuel cell buses. These buses were purchased as part the Fuel Cell Electric Bus Commercialization Consortium Deployment (FCEBCCP) project administered by the Center for Transportation and the Environment (CTE) and funded by the California Air Resources Board (CARB). Three of the ten buses experienced repetitive isolation faults in the high voltage battery system which would cause malfunction of the bus and render it out of service. Staff collaborated with New Flyer to report the issues experienced as part of the warranty process. During initial diagnostic attempts the buses were kept out of service for several months, which created a condition causing the high voltage batteries to become unbalanced (a condition when the voltage difference between battery packs is too high).
New Flyer's engineering team worked with the high voltage battery manufacturer A123 to diagnose the battery modules and identify the root cause; however, this became a challenging task leading to long delays. To expedite returning the buses back to revenue service, New Flyer replaced six new battery modules across the three impacted buses. Once the new battery modules were installed, the isolatio...
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