Thank you for your reply, I've tried searching around for that information on here as well as the web and haven't been able to find anything. Would you please let me know where to look or what you searched for?Some people replace the small size battery with a full size regular car battery. They modify the tie down strap and cable connectors. This gives them a battery that has more power and is substantially cheaper. I found the information either on this forum or another Prius forum a few years ago.