I bought the Met5 jacket over a year ago and there was a process you had to follow to "synchronize" the batteries. The bottomline was it just did not work, so I returned it. This winter, I decided to order another Met 5 because I had read that Northface had redesigned the battery system. I have had the jacket for several months now and have been very pleased with the operation. It worked everytime and the length of battery life is excellent. I use the coat around town and when I ski, turn it on high when on the lift, hmmmm so warm. While I think the price is high, it does do what it says and I am very pleased with the performance.