A voluntary software recall on the 2017 Chevy Bolt EV has been extended to 2018 models, a General Motors spokesman told Green Car Reports on Thursday.

Last month, we reported that some owners of early 2017 Chevy Bolt EVs had failed batteries and would receive new batteries from GM.

The fix also involved a software update to the computer that controls battery output, even in cars that without battery failure. Now the software update is being extended to 2018 models.

DON'T MISS: Some Chevrolet Bolt EVs get new battery pack for sudden loss of power: here's why

Owners of 2018 Bolt EVs should get a letter in the mail in the next few weeks advising them to take their Bolt EVs into their dealerships for the update.

"Though our estimates of affected owners haven’t changed and still remain a small percentage, we are adding yet another level of detection by giving all of our customers the most up-to-date software," GM's Coordinator for Global Advanced Technology Communications Chris Bonelli said in a statement.

The software measures the discharge of each of the cells in the battery pack to make sure they're even. If any cells become overtaxed compared with the rest of the battery, the whole pack can be shut down.

2017 Chevrolet Bolt EV

2017 Chevrolet Bolt EV

The recall will update the software to give drivers more warning before that happens to let them know they need to get their car into a dealership to service the battery pack.

In an emailed statement, the company said:

“General Motors is looking at the entire Bolt EV fleet to ensure everyone has the most updated software available. Through letters we are asking all Bolt EV customers to schedule a service appointment to receive the latest software, including the 2017 owners who received the previously released software calibration. In the event of a cell low voltage condition, this new software increases the accuracy of the range estimation, in addition to providing more warning at low states of charge. We understand this is an inconvenience for some customers to service their vehicles again so soon. However, we want to give our customers the most updated software as soon as it’s available.”