The Chevrolet Volt extended range electric vehicle and its battery pack are both converging on the beginning of the product and process validation stage of General Motors’ development process, which is scheduled to start in February, 2010.

According to Andrew Farrah, the vehicle’s chief engineer, and Bill Wallace, the engineering group manager, the vehicle and the pack have undergone some tweaking after testing. On the vehicle side these have included adjustments to address noise, vibration and harshness issues when running in electric mode; while on the pack and cell side, GM has made minor adjustments in the chemistry.

Wallace commented that the adjustments to the cell were “very small” and that they were primarily made for life.

The company has a fleet of 80 pre-production Volts which have logged more than 250,000 miles of testing and have undergone hot weather testing in Death Valley. In terms of battery development, more than 50,000 cells have been on test, all without failure, and GM has built more than 300 prototype battery packs.

GM has conducted more than 150 tests and modules have gone through high dynamic impact testing; static crush; short circuit; thermal stress; seal integrity; and cell penetration tests.