Positive (+) or negative (-) side for battery disconnect?

[culty]

Pretty simple, as the title suggests. I've read quite a bit over the last few weeks and have seen endless debate over whether a disconnect should be between the battery negative and load, or battery positive and load. I'm not an electrician, but it seems that there is a fair amount of misunderstanding about how power flows, and rather than assume, I'm just going to lump myself into the group of ignorant and misinformed.

I was about to throw my disconnect on the negative side, but the battery disconnect I have (Blue Sea m-Series 6006) shows it being on the positive side. Is there a standard for solar/DC applications? If so, any pointers or references would be hugely appreciated. This is going in an RV, in case that makes a difference.

 

[pollenface]

It depends what colour your disconnect switch is. If it's RED it will look best on the POSITIVE side ?

 

[culty]

It depends what colour your disconnect switch is. If it's RED it will look best on the POSITIVE side ?

I mean, it's red, but I have fingernail polish. ?

 

[Hedges]

If you ground one side of battery (NEC requirement for higher voltages), then switch would go on the other side.

Some SCC internally ground PV(-) and connect it to battery(-), only switching PV(+), which might lead to funny things if battery(-) is disconnected (I haven't thought that all through.)

In a vehicle, old times battery was positive to chassis, now negative (I think for corrosion reasons.)
If this is house battery, perhaps it is floating, but if tied to vehicle charging then I'd negative ground it and disconnect positive side.

If lithium, BMS switches positive side.
And you may want a precharge circuit.