New to jayco battery question

[Bmaciver13]

Hi we just purchased a trailer used and I was wondering if someone knows how to setup a tandem battery pair and what runs off the batteries when you have no direct power? Thanks

[Ela1948]

If you are using 12 volt batteries, you want to wire your batteries on parallel. Meaning positive to positive. Negative to negative. If you are using 6 volt batteries you want to set them in series. positive to negative so that you end up with 12 volts. All your lights, refrigerator assuming that you have propane turned on, water pump, exhaust fans, water heater and furnace will run on 12 volts. AC and non of your 120 outlets will operate.

[RoyBraddy]

Here is a neat diagram of what makes up a 30AMP trailer system. You can see here what normally runs on 120VAC and 12VDC...

The main priority use for your battery is when you are towing your trailer. It is required by DOT that any trailer that has electric brakes installed and is using the public roadways must be equiped with a battery source to operate the trailer electric brakes in the event the trailer becomes disconnected from the tow vehicle going down the road. The idea is to stop the run-away trailer as soon as possible.



Roy Ken

[Bmaciver13]

This is how it is currently set up should there be another negative to negative running. There's two positives coming from the RV already

[clubhouse]

That simply doesn't look correct to me. The picture isn't absolutely clear, but still looks like some wire color confusion exists.

In towable RVs ... Black wire = positive 12v and White wire = ground/negative.

So in your situation you need the Trailers black wire connected to the positive post and trailers white wire connected to the negative post. Then you need to supply your own black/white wires to connected the batteries in parallel -- which is (+) to (+) and (-) to (-). If you have a power tongue jack, that would be another black wire that needs to connect to the positive battery terminal.

[Bmaciver13]

Ok so upon closer inspection the red one is the positive coming from trailer and the black one is positive coming from tongue hitch and white is negative. Does it matter who one the tongue hitch would be hooked up to in a parallel setup?

[Jace817]

I just added a second to mine this weekend. I have a positive to positive and negative negative jumper that ties the batteries together but keeps it 12v. Found the jumpers at wal-mart next the the batteries. I believe they were 6 gauge and 36".

Next I took the negative from the trailer and hooked it to the positive of one battery and took the positive from the trailer and hooked it to the negative. I added a keyed disconnect switch on the positive leg between the trailer and the battery to keep the parasitic loads from draining the battery. I tied the electric brakes and the power jack directly to the battery (jack has an inline fuse) in order to bypass the disconnect. I would like to go back and put the jack through the disconnect as a theft deterant, but the wire wasn't long enough and I didn't have any with me.

[clubhouse]

Originally Posted by Bmaciver13

Ok so upon closer inspection the red one is the positive coming from trailer and the black one is positive coming from tongue hitch and white is negative. Does it matter who one the tongue hitch would be hooked up to in a parallel setup?

Currently you batteries are not connected in parallel. Basically the ways it's wired now, one battery is supporting just the tongue jack and the other is supporting the trailer 12v needs. The first thing you need to do is connect the batteries + to + and - to - . Once you do that it will double the amount of Amp hours available for both the tongue jack and trailer.

Secondly I would clean up the wire colors so everything is consistent on that a frame. If it was me all the (+) connections would be black and all the (-) connections would be white.

Last, there are different opinions on this, but personally I make both the (-) and (+) trailer connections on the same battery. One the batteries are connected in parallel, in reality they are one "battery pack" so it shouldn't matter if you make the connections on one or split it between both.

[Mustang65]

Hope this makes it a little easier..
Don

[Bassdogs]

As far as connecting 6v's in series, just think about an old style flashlite with 2 batteries in the handle. The batteries are stacked on top of each other with a [-] neg pickup usually at the bottom and the [+] terminal at the top of the stack.

On your TT, you don't stack them, but you connect pos from bat 1 to the TT wiring and then the neg from bat 1 to the pos of bat 2 and finally connect the neg on bat 2 to the neg to the TT. Not any more complicated than that.

[Mustang65]

Sorry, not sure if you mentioned 6 or 12VDC batteries
Don