Dual battery charging and common negative

[Gixer]

Hey all,

I think I’m going to fit a dual feed 240v charger (Sterling Pro Sport) for my domestic and engine battery. Just realised the batteries have a common negative at the isolator and was wondering if this will affect the chargers ’brain’.
I was planning to attach the engine battery terminals directly to one feed of the charger and on the domestic side, the other feeds positive to the battery and negative to the load side of the battery monitor shunt.
If there’s a better way to be this I’m all ears ?

 

[RichardS]

My 3 house batteries and 2 engine batteries are all common negative but I have separate solar controllers and one mains charger and everything works fine.

Richard

 

[Bobc]

No, will be fine. I have the same with a Sterling charger.

 

[pvb]

The common negative shouldn't affect anything. The dual feed ProSport charger is unusual in having a pos & neg wire for each output, but it shouldn't be a problem.

 

[BabaYaga]

Just realised the batteries have a common negative at the isolator

This sounds a bit odd...
Do you have the kind of main switch that controls both positive and negative?

 

[Gixer]

Thanks for the responses guys, as usual I was overthinking it ?

BabaYaga, no I have a standard 1,2 both switch on the live but another separate isolator on the negative.

 

[Alan S]

I wold get rid of that negative isolator, it doesn't serve any purpose and is just another potential point of failure.

 

[Gixer]

Funnily enough Alan it did fail recently and I replaced it with a new one.

It will come out along with the 1,2 both switch soon but I’m desperate to get back it the water so that can wait.

 

[PaulRainbow]

Funnily enough Alan it did fail recently and I replaced it with a new one.

It will come out along with the 1,2 both switch soon but I’m desperate to get back it the water so that can wait.

Paint the negative isolator yellow and use it as the emergency switch. when you take the 1-2-B out.

 

[Gixer]

Paint the negative isolator yellow and use it as the emergency switch. when you take the 1-2-B out.

Do you mean turn it into the emergency combine switch or as an emergency cut off?

 

[PaulRainbow]

Do you mean turn it into the emergency combine switch or as an emergency cut off?

Emergency combine, run a cable from the load side of the two isolators.