I finally have a working Hymotion battery pack, again. If anyone has a failure, after their warranty expires, I'd be glad to explain how A123's service arrangement is intended to work and tell you who to contact. My pack died on November 30, 2011, and was fixed, reinstalled, and working again, by June 10, 2012. Part of the delay was due to my own indecision and procrastination, but it still took a couple months (and three trips from upstate New York, to Fitzgerald Toyota, near Washington, DC), to get my pack working again. I guess that's what I get for buying something that I knew I would have make long trips to get serviced. My advice to others is to have regular communication with all three parties who will be involved in your service, and to ask all pertinent questions. Do not assume that everything will happen automatically. Keeping asking questions until you understand what is supposed to happen. Then, ask again, to verify that everyone understands each other, ...and keep asking, at every step of the process, to make sure that the people involved are communicating with each other and that they are making decisions that make sense to you. Verify TWICE (at least) that they are sure that your Hymotion system is REALLY working, before making a long trip to pick it up (or have it reinstalled). Above all, don't be afraid to ask for what you need. These are cooperative and considerate people, but they still might need to be reminded that customers shouldn't be made to pay for service mistakes made by the manufacturer of a product that they have purchased (or by the installer). If all of that sounds a little bit vague, that's because A123 has managed to make me into a satisfied (albeit extremely inconvenienced) customer, and I'd like to give them the benefit of the doubt. However, there are limits to that sentiment, and I will gladly be less vague, if it will help any of you hold their feet to the fire, and get the service that you need, without getting as much of a run-around as I got.