MBTA releases video showing battery exploding on new Orange Line train

BOSTON -- New video from the MBTA captures a battery explosion on an Orange Line train that caused Orange and Red Line trains to be shut down on June 20. 

The battery exploded on an Orange Line car at the Wellington Train Yard. The train was out of service at the time, but the T pulled all of the new trains from the tracks for two weeks as it investigated what went wrong.

The T says an "out-of-range battery temperature reading" caused the battery to overheat, but the problem has been fixed now. 

"A design change was made to increase airflow in the battery compartment and a modification to the temperature sensing circuitry was developed, implemented, and successfully tested last weekend," the T said on Friday.

The MBTA put the new Orange and Red Line cars back into service on July 4.