a little bit..... First,We are hoping the batteries will last longer then 2 years. The 2 years is just the length of time we have done testing so far. The price of replacements will be based on volume. It is hard to project how many units I will be able to buy. We will not want the batteries sitting around long and the amount of volume will effect the price greatly. I have had great feedback from my local customers and also a few other shops with other car markets we will be selling to. If I had to guess, I would say the replacement batteries will be in the Seventy dollar range. I am hoping it will be even cheaper because we would like to make this set up a reasonable option.