I have a 2007 and was just wondering if it's over due. My car has 58k miles and the battery is now six years old. I remember the increase in MPG and longer electric range(enging stays off longer in traffic) after the new 12v main battery. Changed that one when it read 10.1V and would not turn my HID fogs on with the car turned off. The OBD port scanner does not give the voltage for this battery. I searched alredy but no posts on this topic. If you changed the battery already does the car corner even flatter then before? Thanks in advance.

 

It's not going to hurt. Fresh battery will always be beneficial. I would just change them both and forget about them for the next 60k.

 

both of those batteries can last very very long considering they don't get much use. yes, some main 12volt batteries have gone out rather early......but some have over 120k on them and are in perfect shape.

Simple advice. test it. i think it's a 356 cca battery....but it should say on it. any auto parts store should have a battery tester. I wouldn't replace a battery unless it was needed.

 

Interesting points. Has anyone else experienced these changes after replacing the batt?

 

doubt it. it doesn't use that battery when the car is turned on. it uses the HV battery via a DC-DC converter.

 

I couldn't follow the logic either but thought Id ask.