We own a 2012 Volt with 83600 miles and the vehicle is near the end of the 8 year/100,000 mile battery warranty. Historical observation of information on the onboard screen in the car establishes that 12 + kwh would be routinely discharged before the generator took over and the battery power ended. I also monitored charging from the 220 volt charger in our garage, and 13 kwhs plus being used to charge the car to full were not uncommon. Unfortunately, Blink no longer provides charge information, so its been a couple of years since I've tracked how much power went into charging. However, 13 Kwh going in, given the inefficiency of charging batteries, is consistent with 12 plus kwh being available for discharge, and being discharged.
Lately I noticed that the most that can be discharged is 9 kwh, at which point, the generator takes over. I took the car to the dealer today concerned that being able to only discharge 9 kwh meant that over 25% of the range of the battery is no longer useable. Dealer found no error codes, and GM technician contacted by the dealer by phone referenced Document ID 5406682 to assert that the minimum battery warranty capacity was 33.6 Amp/hrs, and that, based on the in shop technicians testing, all cells tested at 3.98 volts, and the battery capacity was at 37.8 Amp/hrs. Basically, GM's position is that the battery is within spec, and the is no warranty claim.
Have others encountered loss of battery capacity issues with their Volts? (Capacity has a direct effect on range - you might not notice how many kwh are capable of being used, and instead see a drop in range). And, as it now appears, GM takes the position degradation of the battery within a range it established is acceptable for purposes of the warranty, yet at the time the purchase of the car was being considered, nothing was disclosed about the 8 year/100,000 mile warranty meaning that, if at or near the end of the warranty period/mileage, experiencing at 25% plus loss of range/battery capacity was acceptable.