Battery Cutoff Switch Install for 6v Batteries

[JoeHTP]

We have a 25' 2017 Flying Cloud. I have purchased a pair of Trojan 6 volt AGMs. As part of the install, I would like to add a three way battery cutoff switch (Off, On Power & Inverter, On Power, Inverter off). I have been looking at different ways to fit a Blue Sea switch the box along with the batteries.

Can anyone that has accomplished adding a cutoff switch in or near the battery box offer an where/how to do it given the space limitation?

Thanks!

[rmkrum]

IIRC, the Blue Sea switches are waterproof. I'm mounting mine on the outside of the battery box, surface mounted with 4 pan head stainless steel screws from the inside of the battery box into Nylock nuts that fit into the recesses in the front of the switch.

Yeah, it could be tampered with...if that's an issue, I think they make ones that lock with a key.

Be sure to size the short battery lead from battery positive post to the switch more than beefy enough to take the inverter as well as the usual house loads. I don't know where you might mount the inverter and house main fuses--perhaps a rather big one right at the battery terminal to protect all the wiring and the switch from excessive current

Be very sure to protect all the exposed cables from chafing, sunlight, and mechanical damage--you're talking a LOT of energy potentially flowing in those cables...

Lewster, chime in?

[JoeHTP]

Thanks for the advice. Follow up question - if you mount on the outside of the battery box (which I think is a good approach), I assume you have to drill holes in the battery box to pass the cables through? In that case, it would seem like you would need 90 degree lugs to connect, since the big cables do not flex?

Joe

Originally Posted by rmkrum

IIRC, the Blue Sea switches are waterproof. I'm mounting mine on the outside of the battery box, surface mounted with 4 pan head stainless steel screws from the inside of the battery box into Nylock nuts that fit into the recesses in the front of the switch.

Yeah, it could be tampered with...if that's an issue, I think they make ones that lock with a key.

Be sure to size the short battery lead from battery positive post to the switch more than beefy enough to take the inverter as well as the usual house loads. I don't know where you might mount the inverter and house main fuses--perhaps a rather big one right at the battery terminal to protect all the wiring and the switch from excessive current

Be very sure to protect all the exposed cables from chafing, sunlight, and mechanical damage--you're talking a LOT of energy potentially flowing in those cables...

Lewster, chime in?

[FishByFly]

This is my setup. You can see the Blue Sea switch outside the battery box in the lower left of the pic. I chose the switch in Black to conceal it a bit.

[JoeHTP]

Thanks for the photo. From what I can tell your cables run in and out of the existing hole in the battery box and into the switch. Do you need to waterproof the entry into the switch, and is some kind of drain hole needed in case water gets in?

Good call on the black box, it blends right in!

Joe

Originally Posted by FishByFly

This is my setup. You can see the Blue Sea switch outside the battery box in the lower left of the pic. I chose the switch in Black to conceal it a bit. Attachment 302609

[FishByFly]

I just wired the switch as it came. I mounted it similarly as rmkrum described with pan head screws and concealed nuts. Nothing special on making it “more” watertight as I am not expecting it to get submerged. Moisture that gets in can drain out the bottom or evaporate.

I did increase the gauge of all wires from here into the batter box and within the box itself. Used all the existing routing. Used lug connections for everything at the battery.

This was the first season that I only have to open the battery box to check the water in the batteries.