2 weeks on my new 2010 Prius battery; it has been flawless as has my Prius (purchased new). I am back up to 50mpg and it drives like new. My mileage was down to 43 and battery wasn't charging up like it used to so decided to replace it out of an abundance of caution. I took it to the shop in NE Portland and Ben got me in and out in less than an hour. I was very impressed with the customer service and product. I highly recommend it.