 All 12 @,@ 400 Chevrolet Volts produced until December 2011 , including all Amperas in stock at European dealerships , were scheduled to receive the safety enhancements . Since production was halted during the holidays , the enhancements were in place when production resumed in early 2012 . Sales continued , and dealers modified the Volts they had in stock . General Motors sent a letter to Volt owners indicating that they could schedule the service appointment to protect their batteries beginning in the last week of March 2012 . General Motors also decided to replace the 120 @-@ volt charging cords in most of the nearly 10 @,@ 000 Volts sold since late 2010 . The new cords were enhanced to add durability , and some of the chargers built after February 5 have the new cords . 
