The first brand-new Red Line train produced by CRCC for the MBTA arrives at the Charles/MGH station in February 2022. Photo by Jack Cao | CC BY-SA 4.0

Add battery mishaps to the growing list of problems that have plagued the MBTA’s newest subway additions.

All new Orange Line and Red Line cars remain out of service Wednesday, two days after an offline Orange Line vehicle experienced a “battery failure” in the Wellington Yard.

“With safety being the top priority, the MBTA has decided to keep all of the new Orange Line and Red Line cars out of service while vehicle engineers and technicians work to determine the root cause of the failure and implement whatever corrective actions may be necessary,” MBTA spokesperson Lisa Battiston said in a statement. “An update on the status of the cars will be provided as soon as the engineering team completes its work.”

It’s the second time in as many months that the T has pulled every new Orange and Red Line vehicle, manufactured in Springfield under a contract with Chinese firm CRRC, from the tracks amid mechanical failures.

In May, an improperly installed bolt-on an Orange Line braking unit disabled a train. Inspectors later found a total of 17 bolts out of 1,584 did not meet proper standards and began returning the trains to service once the issues were addressed.

The hiccup comes as Massachusetts lawmakers prepare to convene an oversight hearing into persistent issues at the MBTA and as federal overseers seek immediate changes to address glaring safety issues at the T.

New CRRC-manufactured cars have previously been pulled from service after a faulty side bearer pad contributed to a March 2021 derailment, due to a problem with bolsters identified in March 2020, as a result of a faulty pad interface in November 2019, and two months earlier after a door leaf opened while a train was in motion.

The cars were originally ordered under the administration of Gov. Deval Patrick, but that first $556 million contract to replace the entire Orange Line fleet and the Red Line’s oldest trains – which came before CRCC had even built its Springfield factory – was expanded by $277 million by Gov. Charlie Baker’s administration in 2016 to include 120 more Red Line cars in what was billed as a cost-saving measure.