I'm planning to "gift" my 2004 Prius with 140K miles on it to my son who lives back East. I've never had any issues with my batteries (either the 12V or the HV). Should I be concerned that there's a good chance he may have to change out either or both batteries in the not too distant future? My thought is to give him the car because he can't afford to buy one. However, if the HV battery goes out, he probably won't be able to afford to replace that either. Thoughts/recommendations?
I doubt the HV battery will go out any time soon. Even people with 200,000+ miles have not had a problem. A 12 V failure is more likely but can be easily replaced. I think your son is lucky. My parents wouldn't even let me drive their Prius. I had to buy my own!
I agree that if you wish to give your son a "break", that you should replace the 12V auxiliary battery now, prior to gifting the car. There is an excellent chance that battery will fail once the car gets into cold winter weather. In addition, if the 100K and 120K mile services were not performed (in particular, engine and inverter/transaxle coolant replacement, iridium spark plug change, transaxle ATF fluid replacement) I'm sure your son would appreciate it if you took care of that for him. The current cost of a 2G traction battery from a salvage yard is around $500 plus shipping. Independent Toyota hybrid service may be available in large metropolitan areas, so this repair would not necessarily cost a large sum.
