Negative/ground connections for 2nd battery

[cfanto]

Hello,

After my previous experience getting stuck out in the water with a dead battery, I am in the process of setting up my rig with a dual-battery (one starting & the other is a Deep Cycle) along with a Perko switch (1-2-All-Off).

My question is in regards to the Negative terminals for the batteries. Can I just hook up my second battery's Negative terminal to the negative terminal of the first battery? Or do I need to run it back to the engine block like how the first battery is connected?

Thanks.

 

[Silvertip]

Re: Negative/ground connections for 2nd battery

It doesn't matter -- electrically they are the same point. The logical point to connect it is the closest. If the two batteries are close to each other, then the negative terminals should be tied together. If the batteries are farther apart, then the engine may be closer -- BUT, if you make the connection at the engine, make sure you connect it at the same point as the ground cable for the starting battery. This avoids any potential "ground loops" that drives electronics crazy.

 

[cfanto]

Re: Negative/ground connections for 2nd battery

Thanks Silvertip!