Adding a battery disconnect

[blubuckaroo]

I normally remove our batteries for the off season and keep them on a Battery Tender, but during other periods of non-use I've been disconnecting the the batteries from the post.
I'd like to add a battery disconnect, since our Passport didn't qualify for such an extravagance.
I've looked at some different types, and some require a hole cut into the chassis to mount the switch, and I won't do that.
What are my options?

[chuckster57]

This one is very popular and I have installed countless number of them.

https://www.walmart.com/ip/MARINCO-701CHRV-Battery-Disconnect-Switch-Knob-Type-On-off-Switch/115356298?wmlspartner=wmtlabs&adid=22222222222111960381&wmlspartner=wmtlabs&wl0=e&wl1=o&wl2=c&wl3=75179190359115&wl4=pla-4578778755914877&wl5=&wl6=&wl7=&%20wl10=Walmart&wl12=115356298_10000001205&wl14=marinco%20battery%20disconnect&veh=sem&msclkid=1d55c2e9f5071196be98a2a5054a4ce0

Argument is positive or negative lead...Manufacturer uses the positive.

[JRTJH]

If you want a "simple and easy to install" BCO switch, Harbor Freight sells a switch that mounts on either the positive or negative battery terminal with the switch built into it. Remove the battery cable, install the device, attach the battery cable to the device and operate the switch. It's $6.99 at HF https://www.harborfreight.com/battery-disconnect-switch-97853.html

If you get into the argument of "positive or negative" and where to install it, just buy two ($14) and install one on each terminal on the battery..... :cool:

HF also sells the "red key type" BCO switch for $7. If you decide to go that route, you'll also need to buy a "gray plastic utility box" and an extra battery cable (or cut your current one and solder/crimp terminals on the cut ends). Then you'll need to locate a place to install the box with the BCO switch in it. That location could be "on the battery box lid" or close to the battery location.

It's easier to just install the "battery terminal device", then as you use it, determine if it is "fancy enough for you" or whether you want to indulge in a more elaborate BCO switch system. The total investment is $7 and about 10 minutes.

[Weldon]

Thank you for this. I've been disconnecting our cables after every use. Didn't realize there were options on the market.:o

[rhagfo]

This one is very popular and I have installed countless number of them.

https://www.walmart.com/ip/MARINCO-701CHRV-Battery-Disconnect-Switch-Knob-Type-On-off-Switch/115356298?wmlspartner=wmtlabs&adid=22222222222111960381&wmlspartner=wmtlabs&wl0=e&wl1=o&wl2=c&wl3=75179190359115&wl4=pla-4578778755914877&wl5=&wl6=&wl7=&%20wl10=Walmart&wl12=115356298_10000001205&wl14=marinco%20battery%20disconnect&veh=sem&msclkid=1d55c2e9f5071196be98a2a5054a4ce0

Argument is positive or negative lead...Manufacturer uses the positive.

X2
This is the switch I installed on our 5er, and loved it would flip to off when we got home from a trip, and two months later batteries still showed a full charge.

[Javi]

The reasoning behind using the negative post for the cutoff is simple... no ground / no power flow...

If you choose the positive post just be sure to put the switch before any connection to a terminal. This is why there are parasitic draws even with the factory installed cutoff switches.. by law they cannot completely disconnect power from some safety features.

[LewisB]

Also, obviously, if you use the "battery terminal post" type switch and you have multiple batteries, you will need to install the post switch at every battery.:facepalm:

[chuckster57]

Also, obviously, if you use the "battery terminal post" type switch and you have multiple batteries, you will need to install the post switch at every battery.:facepalm:
Not really, just the lead to the trailer if all your doing is disconnecting the "trailer".

[travelin texans]

Also, obviously, if you use the "battery terminal post" type switch and you have multiple batteries, you will need to install the post switch at every battery.:facepalm:

NOPE! Just the primary positive to the trailer or the negative cable going to ground.

[travelin texans]

Also, obviously, if you use the "battery terminal post" type switch and you have multiple batteries, you will need to install the post switch at every battery.:facepalm:

NOPE! Just the primary positive to the trailer or the negative cable going to ground.
If you use the disconnect that separates in the middle & install it on the positive cable you will have sparks, on negative you shouldn't.

[LewisB]

Right. No need to install one on the tow vehicle or the DW's car. Batteries for a residential fridge need special consideration - there's probably other scenarios where separate batteries are used for boondocking or starting the generator. I assumed that we were talking about standard trailer batteries connected to the trailer.

It is fairly common to find 2 or more batteries in a bank that can not be fully interrupted with the OE "disconnect" system. If you have a trailer with more than one battery connected as a bank that you want to disconnect and you choose to use the battery post connection/switch shown by John in his post, then you will need to install a switch on each trailer battery. Sorry if that wasn't clear.

[chuckster57]

Right. No need to install one on the tow vehicle or the DW's car. Batteries for a residential fridge need special consideration - there's probably other scenarios where separate batteries are used for boondocking or starting the generator. I assumed that we were talking about standard trailer batteries connected to the trailer.

It is fairly common to find 2 or more batteries in a bank that can not be fully interrupted with the OE "disconnect" system. If you have a trailer with more than one battery connected as a bank that you want to disconnect and you choose to use the battery post connection/switch shown by John in his post, then you will need to install a switch on each trailer battery. Sorry if that wasn't clear.

Unless you have separate battery(s) for a residential fridge, then again you only need one disconnect at the power FEED TO THE TRAILER no matter how many batteries are in that "bank"

[LewisB]

Unless you have separate battery(s) for a residential fridge, then again you only need one disconnect at the power FEED TO THE TRAILER no matter how many batteries are in that "bank"

Ok, didn't mean to highjack the thread over the issue. Since you seem determined to ignore what I actually say I'll just hope that others will actually read what I wrote and capture what I was saying. This was not a recommendation on my part. I too would choose a single switch to interrupt the negative side of the entire power feed. My point was simply that you can't use a "post switch" and interrupt only one battery in a bank and expect that to accomplish a complete disconnect. With that, I'm done.

[blubuckaroo]

Thanks everyone. I’m going with the post style. The funny thing is, I first went to NAPA and they wanted $46 for one that looked just like the one at Horror Freight for $7. So I bought two from HF. The other I’ll use on my smaller hunting trailer.I figure these are probably made to handle a starter load. My little travel trailer won have near that load.

[JRTJH]

Thanks everyone. I’m going with the post style. The funny thing is, I first went to NAPA and they wanted $46 for one that looked just like the one at Horror Freight for $7. So I bought two from HF. The other I’ll use on my smaller hunting trailer.I figure these are probably made to handle a starter load. My little travel trailer won have near that load.

According to the HF website, the "terminal mounted BCO switch is rated @12 volts, 500 peak/125 continuous amps. A 6 gauge battery cable 2' long will burn up (or melt the insulation) at around 150-200 amps. If you think about the two mini-breakers on the bulkhead crossmember on your trailer, one is 40 amps and the other is 30 amps, so the max that could ever go through the battery cable (and the BCO switch) is 70 amps. That is, unless you wind up with a direct short on the battery cable, and then, you'd be better off if that switch "burned up quicker than the trailer.....

[Urbish]

A simple reminder for all involved that your RV battery is likely providing power to your trailer brakes in the event of a trailer separation that involves pulling your emergency cable. If your battery is manually disconnected when you are towing (by switch, terminal removal, whatever), your brakes won't set in a separation. So make sure that battery is connected before you tow!

[Customer1]

The reason to switch the positive in any towable is to avoid disabling the breakaway braking system. The breakaway switch is connected to power prior to the disconnect allowing the breakaway to operate regardless of switch position.

[travelin texans]

The reason to switch the positive in any towable is to avoid disabling the breakaway braking system. The breakaway switch is connected to power prior to the disconnect allowing the breakaway to operate regardless of switch position.

But to totally disconnect ALL parasitic drains you need to disconnect a battery cable, by doing this you disconnect the breakaway power.

[skids]

But to totally disconnect ALL parasitic drains you need to disconnect a battery cable, by doing this you disconnect the breakaway power.

Fortunately, a lot of campers will want to keep the contents of the refrigerator cold, thereby switching on the battery (and the propane).

[rhagfo]

The reason to switch the positive in any towable is to avoid disabling the breakaway braking system. The breakaway switch is connected to power prior to the disconnect allowing the breakaway to operate regardless of switch position.

Well if the disconnect is on the negative cable the breakaway will not work as the battery is not grounded, therefore no voltage.

If you really worry about the breakaway, take the positive wire and attach directly to the battery positive post, the breakaway switch is normally open and will NOT create parasitic draw on the battery.

[flybouy]

I installed a disconnect in the lid of the battery box which resides on the tongue right behind the battery. I installed the switch on thw ground cable. No issue with forgetting even with my feebel mind. When getting prepared for departure the last thing I do is disconnect shore power, store the cord, then raise thew tongue jack to hitch height. If the jack don't work then disconnect is on.

[sourdough]

I installed a disconnect in the lid of the battery box which resides on the tongue right behind the battery. I installed the switch on thw ground cable. No issue with forgetting even with my feebel mind. When getting prepared for departure the last thing I do is disconnect shore power, store the cord, then raise thew tongue jack to hitch height. If the jack don't work then disconnect is on.


That's the way mine was; if the disconnect was thrown jack no workee....no hitch the trailer. :D

[Customer1]

But to totally disconnect ALL parasitic drains you need to disconnect a battery cable, by doing this you disconnect the breakaway power.

Nope, you simply break the positive after the breakaway connection leaving the breakaway switch as the only thing with power. The breakaway won't be a drain on the batteries unless you pull the pin.

If you break the negative, everything including the breakaway will be powerless.

[Customer1]

Well if the disconnect is on the negative cable the breakaway will not work as the battery is not grounded, therefore no voltage.

If you really worry about the breakaway, take the positive wire and attach directly to the battery positive post, the breakaway switch is normally open and will NOT create parasitic draw on the battery.

Correct, but if you break the negative, there is no way possible to power the breakaway.

[rjniles]

I installed a switch like post #2 on the side of my battery box. Switched the positive terminal.

[ckittila]

Whatever you do, don’t buy the cheapest switch on eBay for your disconnect. Spend the extra dollars to buy a quality switch or you will get stuck in the future when the cheap internal connections decay. Remember—all circuits on battery use this switch and it needs to be able to hold up.

[travelin texans]

Nope, you simply break the positive after the breakaway connection leaving the breakaway switch as the only thing with power. The breakaway won't be a drain on the batteries unless you pull the pin.

If you break the negative, everything including the breakaway will be powerless.

I'm talking using the disconnect while rv is being stored & breakaway not needed.
Also if I decide to move the rv with the cable removed the jacks won't work, nor the breakaway, til the cable is reconnected.
I talked to fellow rver that said while his rv was in storage with the disconnect off, the breakaway still had power, that some ahole came through the storage pulling the breakaway pins on the majority of the RVs thereby burning up the switches, brake wiring & ruining batteries. With the negative cable removed that can't happen.

[Mikelff]

I normally remove our batteries for the off season and keep them on a Battery Tender, but during other periods of non-use I've been disconnecting the the batteries from the post.
I'd like to add a battery disconnect, since our Passport didn't qualify for such an extravagance.
I've looked at some different types, and some require a hole cut into the chassis to mount the switch, and I won't do that.
What are my options?

If you have the dual posts, screw down type, this works great.
https://www.amazon.com/dp/B07JZ8MKL2/ref=cm_sw_r_em_api_glt_fabc_KE5G8J8JQ9FQN9GNJEZG?_ encoding=UTF8&psc=1

[rhagfo]

If you have the dual posts, screw down type, this works great.
https://www.amazon.com/dp/B07JZ8MKL2/ref=cm_sw_r_em_api_glt_fabc_KE5G8J8JQ9FQN9GNJEZG?_ encoding=UTF8&psc=1

The type you selected would require opening the battery box to trun the switch.

https://www.amazon.com/dp/B07JZ8MKL2/ref=cm_sw_r_em_api_glt_fabc_KE5G8J8JQ9FQN9GNJEZG?_ encoding=UTF8&psc=1

The one from post #2, that Chuck provided a link to is the same I have, easily remotely mounted, and also easy to see if on or off. My battery box is sealed with about six or so screws.

https://www.walmart.com/ip/MARINCO-701CHRV-Battery-Disconnect-Switch-Knob-Type-On-off-Switch/115356298?wmlspartner=wmtlabs&adid=22222222222111960381&wmlspartner=wmtlabs&wl0=e&wl1=o&wl2=c&wl3=75179190359115&wl4=pla-4578778755914877&wl5=&wl6=&wl7=&%20wl10=Walmart&wl12=115356298_10000001205&wl14=marinco%20battery%20disconnect&veh=sem&msclkid=1d55c2e9f5071196be98a2a5054a4ce0

[Diver]

On anything I put a switch on I always put it on the Negative cable ...
it will not corrode as a Positive cable will

[Bill-2020]

Ok. I bought and installed this last year: https://www.bluesea.com/products/6006200/m-Series_Mini_On-Off_Battery_Switch_with__Knob_-_Black

The manufacturer's wiring diagram showed connecting to the positive terminal. So I did (it cuts ALL power from the camper except the jack.) So by using the positive terminal, instead of the negative, what kind of a mess have I gotten myself into and is it merely a preference by most or a requirement? :banghead:

[Diver]

what kind of a mess have I gotten myself into and is it merely a preference by most or a requirement? :banghead:[/QUOTE]

wont hurt anything .....
I was just explaining my preference because I i have seen corrosion on switches in truck applications ..where the intent is to totally disconnect power

[ChuckS]

Personally Battery disconnect switches are just another source of potential problems to induce into the 12 volts system... Id have just remove the negative terminal from battery and brought the battery home and out ion a maintainer...

Yea its a slight pain but the battery will always have a full charge this way.. I cant tell you how many folks I have helped troubleshoot NO 12 volts from battery issue down to a battery disconnect switch...

But.. you've got it installed and Id have installed it on the negative side.. Some passing thru yanks your battery break away cable and you will come back to more than a dead battery

[Diver]

.. Id have just remove the negative terminal from battery and brought the battery home and out ion a maintainer...

Yea its a slight pain but the battery will always have a full charge this way.. I cant tell you how many folks I have helped troubleshoot NO 12 volts from battery issue down to a battery disconnect switch...

But.. you've got it installed and Id have installed it on the negative side.. Some passing thru yanks your battery break away cable and you will come back to more than a dead battery[/QUOTE]

I do remove Battery in winter... the disconnect is for when its sitting in the yard and not being used for a few weeks and not plugged in to shore power

[Weldon]

Its not pretty but its installed with new cables. Had to replace cable going to negative terminal as well because it was too short to reach the disconnect switch. You can't see it, but there is silicone where I drilled the 1" hole for the switch. Had to grind some of the round plastic part of the switch to make it fit with the angles of the box lid.
I sprayed it with black when finished and put the extra cable inside the battery box (forgot to take a pic).

Then I went home and put a bunch of stuff on CL (old WDH, 30 and 50 amp surge protectors, 4 bike bumper rack, curt hitch for the wifes Journey). Within 5 mins, received 4 scam texts. Now I remember why I put off posting on CL. "Can I send you a code to verify that you are a real person?" I received that 3 times from different people with LA area codes...im in GA! :banghead:

[Bill-2020]

Craigslist is horrible. Once the scammers have their fun the bogus responses tapper off to nearly non-existent. I have a new, in the box, camper cover that was given to us by a neighbor who sold his camper. This cover is too big for ours and I told him I’d sell it and do the work selling it and then split the proceeds with him. It’s been over a year now, one bite of a low ball offer. We’ll hold out for a decent offer.

[Jax]

I personally like this in place of the "fuseblock" on the frame. Breakaway, hitch are attached directly to the batteries and are not shut off with this.

https://smile.amazon.com/gp/product/B07FD49PB9

https://images-na.ssl-images-amazon.com/images/I/61P19JhuE7L._AC_SL1500_.jpg