[CVTitan05]

Hey guys, i have a 14 ft enclosed trailer, It is equipped with lights inside but the lights only work when the truck is hooked up, and with the trucks running lights on....

So im going to be installing a deep cycle battery that i have sitting in my garage. The trailer is already wired for a battery (my dad did it a while back).

But i want it to charge while my truck is hooked up, that way i dont have to worry about the battery being dead after I get where im going. But i dont want it to drain my truck battery while its not running.

Has anybody successfully done something like this? I think i could do it with a relay, wire it to ignition power, then run a 8ga wire from the battery to the back, and through the 7pin plug. Would this do the job?

Let me know what you guys have done!
Thanks!

 

[4mula1fan]

You can put a kill switch inline to disconnect the truck when you are parked. Check the aux pin to see if it's hot.

 

[CVTitan05]

Actually i just did more searching in the forum, and it seems the truck is already equipped with a relay that will charge the trailer while the key is in the "ON" position, so Nissan did exactly what i wanted to do!

Now to actually test if it does...

 

[GalaxyPro4X11]

Actually i just did more searching in the forum, and it seems the truck is already equipped with a relay that will charge the trailer while the key is in the "ON" position, so Nissan did exactly what i wanted to do!

Now to actually test if it does...

My 2011 would charge the batteries in my fifthwheel while driving to said location. Never drained the battery when parked either.

 

[4mula1fan]

Your brake controller will still be hot. I think that circuit is the one that will drain your battery if left hooked up.

 

[CVTitan05]

Just went out with a multimeter and checked, with key off, no pins are hot, with the key on, there is positive 12.2v at the upper left (which is auxiliary power). What you posted 4mula1fan is the 7 pin round connectors, while we all have 7 pin flat connectors built into the truck.

Not entirely sure how i can measure how many amps it will actually give, but for me, im sure it will be enough with just some lights.

 

[Indy]

Actually i just did more searching in the forum, and it seems the truck is already equipped with a relay that will charge the trailer while the key is in the "ON" position, so Nissan did exactly what i wanted to do!

Now to actually test if it does...

Yeap, and I love it. If I forget to disconnect the battery on my camper when I store it, the battery is dead and all my jacks on it are electric, so comes in handy to just hook up the truck wiring and can use the electric jacks and let the battery charge up.

 

[HRTKD]

I've left my Titan connected to my trailer that has brakes. I haven't detected any problems, but I wasn't specifically looking for any drain.

On my toy hauler I have a 160 watt solar panel. It keeps the dual 6v batteries charged up at 100%. When I go down to the storage yard to work on the trailer I crank up the radio and lights without any battery worries.

 

[MartyG007]

You've discovered that the Titan battery and alternator are only available to the jack when the ignition is on. That is correct. Let me add one caution, maybe not to you, but to those of us who have a converter in the trailer. (a converter becomes alive when the trailer is plugged into the campground and provides 12VDC to charge the trailer battery.)
Avoid plugging in the trailer to shore power if the 7-pin is still connected to the truck, and certainly if the truck is running. From the above description, you can see that you'd have TWO "chargers" (the converter in the trailer and the alternator in the truck) both charging a tied-together system of two batteries. The components on each end are expensive; I don't want them fighting each other.

 

[CVTitan05]

That is an interesting theory, I would think that the truck would have a built in back feed device of some sort, to prevent something like that? Im sure someone has had that happen to them, more than one time... Id be curious to find out the truth behind what would happen.

 

[honda250xtitan]

yup its a great setup. charges my dump trailer all the time. it keeps up unless i do 4-5 dumps a day. which is extremely rare. about once year i need to put the trickle charger on the dump trailer battery for a day.

 

[MartyG007]

That is an interesting theory, I would think that the truck would have a built in back feed device of some sort, to prevent something like that? Im sure someone has had that happen to them, more than one time... Id be curious to find out the truth behind what would happen.

Nope. Follow the white/blue wire back, through the double relay contacts, to the 30 amp fusible link J. No diode or one-way device here. The two 12VDC systems are tied when the relay is energized.

 

[Indy]

Nope. Follow the white/blue wire back, through the double relay contacts, to the 30 amp fusible link J. No diode or one-way device here. The two 12VDC systems are tied when the relay is energized.

But it still wouldn't be any different than starting a vehicle with a battery charger or jumper cables hooked up, something a lot of people do all the time.

Could damage occur, sure if they system on the trailer is faulty, but the risk would be pretty low as you just have to charging systems in parallel, so you are just increasing the current source available, not really spiking the voltage as it will not go higher than the highest source.

 

[MartyG007]

But it still wouldn't be any different than starting a vehicle with a battery charger or jumper cables hooked up, something a lot of people do all the time.

Could damage occur, sure if they system on the trailer is faulty, but the risk would be pretty low as you just have to charging systems in parallel, so you are just increasing the current source available, not really spiking the voltage as it will not go higher than the highest source.

I agree, the risk is low; I'm just reminding people about what's going on. As a matter of practice, when using a charger or jump start, I also disconnect them as soon as the jumped car starts. Based on what I read on the travel trailer boards, the converters are known to fail fairly easily.