# Battery Disconnect Switch



## wrangler

Our new Outback has a battery disconnect switch. It is inside and has the red key type that has off at 12 o'clock position and on at 3 o'clock position. When you are connected to shore power at a site or home when you are winterized do you have the key on or off. When travelling down the road should the key be turned off. Also when dry camping on or off. The manuals that came with the TT has no info on the switch at all on how to use it. I google it and get different answers. Thanks for any info.


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## ED_RN

The switch I installed disconnects all battery power. I'm assuming yours does as well. You would want it off after winterizing. The small drain from things like the propane alarm will completely drain the battery over a period of time. The worse thing for a battery is to sit uncharged.
I would guess any time you are using the trailer you would want it on for the following reasons. Almost everything in the TT including the fridge have a control panel that runs off of the 12 volt side as do all of the lights. If you want to use any of those appliances while driving or dry camping you will need 12 volt. More importantly the brakes need 12 volts as well. If the trailer gets power from the tow vehicle the service brakes will probably work but the emergency brakes, hopefully you will never need them, that come on should the trailer become disconnected will not work. The advantage to having it on when on shore power is that it will keep the batteries charged and the fridge will continue to work if you lose 120 v power to the trailer.


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## H2oSprayer

If your unit came with a factory installed battery disconnect switch (such as the OP is asking about) the breakaway switch for the brakes is not effected by the disconnect switch. However, if your disconnect switch was installed aftermarket, all bets are off as to what it shuts off.

As far as the operation of the switch, when we use our camper is it in the on position the entire time, regardless if we are plugged into shore power or not. If the camper is in storage, the switch is off, keeping the battery from having a parasitic drain.


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## wrangler

Thanks for the info. It makes sense now. It is a factory disconnect switch. I was getting mixed up on the off/on positions. You could easily think that the on position means the battery is disconnected and the off position means the battery is connected.


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## Leedek

An added benefit to having it ON while tooling down the road is the batteries will get charged through the tow vehicle's charging system.







I say this but remind my Outbackers friends that the charging only works if the "+12 Volt Battery" terminal ( see photo) of the connection gets powered. I traveled for years with two different trucks before I knew that there had to be a 30A fuse in the fuse box under the hood my Silverado. I installed the fuse and viola, I had 12 volts on the pin and my trailer got charged by the time I reached the next overnight stop.







Live and learn.

*Pin Out for 7- way connection








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Everything you wanted to know about trailer wiring is here at e-Trailers I do not work for e-Trailers but they have a lot of great information online about ever thing RV. Enjoy!


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## GodFather2u

Leedek said:


> An added benefit to having it ON while tooling down the road is the batteries will get charged through the tow vehicle's charging system.
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> I say this but remind my Outbackers friends that the charging only works if the "+12 Volt Battery" terminal ( see photo) of the connection gets powered. I traveled for years with two different trucks before I knew that there had to be a 30A fuse in the fuse box under the hood my Silverado. I installed the fuse and viola, I had 12 volts on the pin and my trailer got charged by the time I reached the next overnight stop.
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> Live and learn.
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> *Pin Out for 7- way connection
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> Everything you wanted to know about trailer wiring is here at e-Trailers I do not work for e-Trailers but they have a lot of great information online about ever thing RV. Enjoy!


Okay so if I'm reading this correctly, my truck is charging my batteries as I'm tooling down the road. So does it also charge the battery when I'm plugged in at home?


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## Snow

GodFather2u said:


> Okay so if I'm reading this correctly, my truck is charging my batteries as I'm tooling down the road. So does it also charge the battery when I'm plugged in at home?


What plugged into what ?? Truck into trailer ?? Trailer into 120v outlet ??


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## GodFather2u

Snow said:


> Okay so if I'm reading this correctly, my truck is charging my batteries as I'm tooling down the road. So does it also charge the battery when I'm plugged in at home?


What plugged into what ?? Truck into trailer ?? Trailer into 120v outlet ??
[/quote]

Plugged into 120v outlet. Does the switch need to be on to charge? Or should it be in the off position?


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## GodFather2u

robertized said:


> Okay so if I'm reading this correctly, my truck is charging my batteries as I'm tooling down the road. So does it also charge the battery when I'm plugged in at home?


What plugged into what ?? Truck into trailer ?? Trailer into 120v outlet ??
[/quote]

Plugged into 120v outlet. Does the switch need to be on to charge? Or should it be in the off position?
[/quote]

Buddy let me see if I can help by giving you some basic information on the battery on your trailer and how it is used. To start with Travel/Camping trailers are designed to be self contained so this is why the primary appliances (Ref, Stove, Furnace, Water Heater, Lights, Safety Devices/ Detectors) work off of 12V DC and or Propane fuel. When connected to Shore Power, a Generator or even using an Inverter you can take advantage of the 120V AC Features/Appliances in or added to the trailer. The Converter/Charger that comes installed in the trailer has two primary functions 1- supplying 12V DC power to the trailer in place of the battery, and 2- charging the battery, while connected to a 120V AC supply. The disconnect switch on the battery is for convince, and is normally used to disconnect the battery while the trailer is in storage, unless you have a constant 120V AC connected to the trailer. While in storage a battery will lose its charge over time this is normal but not usually harmful. If the battery is still connected there are small loads that will drain the battery down to a level that is damaging to it. The best way to charge the battery is through the on-board converter/charger (3-stage) which is designed to charge Deep Cycle batteries. Being connected to the TV while going down the road does a good job also, if it is long enough to complete the charge. In our truck to get the charging feature to work through the trailer connection I had to install a Relay and Fuse, in the fuse box under the hood of the truck (supplied with the truck). The reason for the relay is so that when the trailer is connected to the truck, the truck battery/charging system will not be connected to the trailer unless the ignition switch is turned on and hopefully with the engine running. So finally to get to your question about the battery disconnect switch, during normal operation (using the trailer) the disconnect switch stays turned on keeping the battery in the system. I hope this has been helpful and Good Luck. 
[/quote]

Wow!! Thanks buddy appreciate the education as always. I'm looking forward to more on this site. Thanks again everyone


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## Snow

GodFather2u said:


> Plugged into 120v outlet. Does the switch need to be on to charge? Or should it be in the off position?


Ok, now I get your question .. Yes with a battery disconnect switch installed, you'll have to have the battery switch turned "ON" in order to have the trailers power converter charge the battery.. Same goes for when towing, switch "ON" for your truck to charge the battery.. Think of it this way, anytime you want to use or charge the battery you must turn the switch on ..


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## Oregon_Camper

Here is the switch I installed. I went with a switch that would allow me to use 2 sets batteries. I thought I might add more batteries (move to 4 x 6v's) in the future, but haven't done that yet.


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