How to Install a Master Battery Disconnect Switch on a Travel Trailer or RV 

I was wrong it should be the positive you were right all along! Sorry

​@chasetan1059 no, you're right. Always hook these to the ground

Read lol

If you look at Grainger and McMaster-Carr battery cut-off switches, they are all designed for the NEGATIVE polarity.

As an Electrician I agree. Positive it is.

@@charleshansen3393hey I’m wanting to isolate 2 bat banks with 1 shutoff switch.And Y from Solar charge controller to the second shutoff switch to select which bat bank gets charged. Have 2 90ah agm bat in front and 1 100ah lithium in a outside closet .I guess hook both banks up to inverter and just switch between banks.I’ll also have to switch the charge controller between agm n lithium for proper charge.Sound right?

neg on rv positive boat. If you put tool on positive against frame bzzzzz,.

Only problem with that is other devices in the car may have local grounds, so if the hot is still on, the drainage will occur.

@arowe2140 lol. No. The battery has to be grounded for it to drain. If the battery itself is not grounded the circuit is not complete. It cannot drain.

@@ridge69 that’s simply not true…I have a disconnect on my battery ground and still have a parasitic drain in my 1973 Chevy blazer…The other accessories things still turn on with key on despite the battery not being grounded….There are other grounds in and around the car….so I get what you’re saying but it simply isn’t true.

@arowe2140 it simply is true. If the battery isn't grounded there is not a complete circuit and it cannot be draining or anything powered by it be turning on. You may have a disconnect on main cable, but there must be another small wire attached to terminal post that is grounding battery. It will not work no matter how many things are grounded to the frame unless the battery is somehow connected to the frame. The cable connection at the post likely has a large wire and a small wire coming out if it. If so both of these have to be run through the disconnect. To prove my point unhook the negative terminal and see that nothing is touching negative terminal and none of those things will light up unless they have an accessory power source. This is why before hooking up a stereo, starter, or anything electrical they say to disconnect the negative battery cable

@@ridge69the only other wire on the ground terminal is for the remote relay that I use to connect and disconnect the ground. There’s no way that the rest of the car can be trying to ground through the relay.

It is. He made a mistake. 😃

Yes. It’s only you because you can read. 😃

That was going to be my question as well

You cna do ut either way. You can leave the batteries connected as they were and just intercept the wire going to the inside of the rv.

If you have a 1,2 ,or both switch, which i prefer you would want them both on the switch

Yah there’s a carbon monoxide detector that drays

that what it is about....the parasitic draw. You can place a trinkle charge on the battery to keep it up.

Same here. Also, wouldn't a switch on the negative side allow a short if the positive side somehow came into contact with the the frame?

You could run a bead of silicone around where the switch sits against the battery cover or whatever you're mounting it to.