single ground for dual battery?

[Donald]

I was getting a 2nd opinion on replacing one or both batteries in my Dodge Ram (from the Interstate company), and they were strongly suggesting I run a ground cable battery to battery. Currently both batteries ground to the vehicle.

 

[mount]

Originally Posted By: Donald
I was getting a 2nd opinion on replacing one or both batteries in my Dodge Ram (from the Interstate company), and they were strongly suggesting I run a ground cable battery to battery. Currently both batteries ground to the vehicle.


I would base it on the quality of each battery's ground to the vehicle. If you have a good quality connection for each battery, nothing beats a big hunk of metal to connect them. Plus a decent sized cable running across the width of the vehicle sounds expensive.

 

[eljefino]

Are they grounded to the engine block or chassis? Block should be preferred as that's the return circuit for the starter draw. Maybe then run 10 ga wire between each battery and then off to a fender for body ground and finally a strap from the engine to the body as well.

 

[dparm]

I thought most engines have multiple grounds?

 

[JHZR2]

Originally Posted By: dparm
I thought most engines have multiple grounds?


+1, or at least multiple bonding pathways to the chassis.

 

[ARCOgraphite]

Be careful with GND circuits, hodgepodge GND scheme without verification may really mess up RFI EMI injection into the engine management - cars are noisy place and spark intervals and injector intervals may overlay data packet xmission and make EM go silly.

 

[Eddie]

+1 ARCO. One HD ground to the engine block and one ground to the chassey is all that is needed. Ed

 

[Donald]

Originally Posted By: Eddie
+1 ARCO. One HD ground to the engine block and one ground to the chassey is all that is needed. Ed


Did you understand there are two batteries? From the factory each battery is grounded to the frame and/or block not to each other.

 

[rfeir]

In my high quality sail boat, both the house and starter battery are tied together at their ground posts with one ground line to the motor. This seems to be standard practice in the marine environment.

 

[Donald]

Originally Posted By: rfeir
In my high quality sail boat, both the house and starter battery are tied together at their ground posts with one ground line to the motor. This seems to be standard practice in the marine environment.


In my boat they are also.

 

[Eddie]

I do assume that the battery grounds are tied together.

 

[Donald]

Originally Posted By: Eddie
I do assume that the battery grounds are tied together.


That was my question in the first place. There is not a wire going from one battery negative to the other. There is for the positive.

The person at Interstate suggested I add a wire connecting the two negative terminals.