Charged me for a new Interstate battery and I still have my 4-yr old factory battery in there. I wish I had looked under the cover sooner. The Aux battery is so hidden - it's nearly impossible for me to check if they replaced that. I hope they did, but it's hard to give them the benefit of the doubt. Update - they did refund me the cost of the battery they did not install when questioned about it. There was no refund for labor or tax on the battery.