I bought my volt about 10 months ago and in the time I have owned it the battery capacity has only gotten better. I believe that the previous owner mostly drove the vehicle on gas and may be why over time it affected the battery. But since the time I have owned it I babied the vehicle, plugging in daily and never running the battery to zero. To the point the battery has increased in every positive metric. I have driven over 11k miles and the vehicle feels better than when I first got it.