A friend of mine came to me with his system that quit working a few weeks back and was hoping I could fix it since I have some experience.

He had this dual battery system installed in his Jeep around 4-5 years ago and it had been working great.

After my diagnosis what I discovered was that we are only getting 6.36 volts of the 2nd battery. The starter battery is giving 12+ volts just as normal, so its ok. I tired starting the car and I still get just 6.36 volts off the 2nd battery.

I have never worked on a dual battery system, but I should still get 12 volts off the 2nd battery right?

Im thinking he just needs to replace this battery and the problem will be fixed.

Any help is appreciated.

Thanks!

 

yeah, sounds like you have a dying battery... 4-5 years is the normal lifespan for a typical battery...

 

Ok just wanted the confirmation before goiing out and buying a new a battery.

Thanks!

 

you can get the battery checked at like kragen or so.

 

ya it sounds like it maybe done for, as it sounds like its set up exactly the way my 2nd battery is; so it should keep charged

 

With a dual battery system you should really invest in a battery isolator solenoid. It keeps the batteries from discharging each other and the batteries will last longer.