isolating truck battery, from trailer battery except to charge

[Splat]

I just want to see if anyone has a better idea than I do.

I'm in the middle of modifying my enclosed trailer. I use it for a variety if uses including hauling my larger rc planes and helicopters, also as a mobile workshop while at the flying field, also for hauling my atvs and a seudo camper while riding in remote areas.

I have a onboard converter so I can plug into 110v and charge the batteries onboard, also it supplies the 12vdc to run the accessories while on household current. Ok here's what I want.... I want to be able to isolate the trailer battery from the truck battery when I'm at the flying field using the accessories and charging my flight packs, also for instances where were running all the lights(lots of them) for loading and unloading the atvs, but when I start the truck back up I want to charge through the trailer wiring.

My truck is a 2007 dodge RAM, and the trailer wiring is wired direct to the battery. Besides installing a switch inline in the trailer the only options I can think of is using installing a relay in line in the trailer harness, running off an ignition switched 12v. Or installing a battery isolation under the hood. Bank one would go to the truck battery, and bank 2 would go to the trailer wiring harness. This would allow separation, but also allow trailer battery to be charged while heading home and such.

Am I missing an option here? Would an isolatior still work correctly with no battery normally on the second bank unless the trailer is hooked up?

Bill

 

[Lion hunter]

Re: isolating truck battery, from trailer battery except to charge

Isn't unhooking the plug-in to the truck an option? I would think that would be the simplest method. 7 prong plugs have a prong for charging so if that wired in it should charge the battery when towing. When unhooked and the converter is plug in it should run things that way. Maybe I'm not understanding what you are trying to do.

 

[MTboatguy]

Re: isolating truck battery, from trailer battery except to charge

Bill Isolation units have been around for decades now, they work, just as you want, I used to install them all the time when I did RV work. In this day and age, this is really pretty simple technology..you can get them in many different amp configurations, and yes, they do work.

You might check your owners manual, many trucks with towing packages have had them installed from the factory for many years now..even if you don't, installing an aftermarket unit will allow all normal functions without the trailer plugged in, the only time it comes into play is when it senses the second load of the trailer, other than that, you vehicle functions just like it was not there at all.

 

[Splat]

Re: isolating truck battery, from trailer battery except to charge

Isn't unhooking the plug-in to the truck an option? I would think that would be the simplest method. 7 prong plugs have a prong for charging so if that wired in it should charge the battery when towing. When unhooked and the converter is plug in it should run things that way. Maybe I'm not understanding what you are trying to do.

Yes unplugging is an option. I would just rather make it as full proof as possible, that's all.

BIll

 

[MTboatguy]

Re: isolating truck battery, from trailer battery except to charge

Yes unplugging is an option. I would just rather make it as full proof as possible, that's all.

BIll

There is no reason to unplug if you have an isolator installed and working correctly, it is simply an electronic switch that turns off when it senses no load from the trailer ..as I said, you might already have one installed on your truck if it came from the factory with a towing package.. The isolator will not send any juice to the charge circuit on the trailer plug if there is no trailer plugged in with a battery in the circuit..

The purpose of the isolator is to isolate the two batteries from each other so they don't draw off each other...very simple to hook up and very simple to use..not complicated at all. All of them that I have installed, you have one wire from the charging source, and then one wire to the truck battery and one wire to the trailer battery and the only time the system in energized is when they are both hooked up, when the trailer is not hooked up, the switch is in the position to charge the truck battery as normal...

Do a google search for battery isolator, and you will see many different ways they are used, also there is information on doing the same thing with a relay..

 

[EJ42955]

Re: isolating truck battery, from trailer battery except to charge

Another thing to check, does the charging system of the truck put out enough to charge your trailer battery?

However, if you connect the trailer to 110vac, didn't you say it charges your trailer battery? Then why do you need to charge it going home? Or, did I misunderstand?

I guess I was really interested in seeing pics of your trailer, as I too fly R/C planes and helis. Gonna need a trailer myself, eventually. Planes keep getting bigger, and hauling too much equipment.

EJ

 

[Splat]

Re: isolating truck battery, from trailer battery except to charge

Bill Isolation units have been around for decades now, they work, just as you want, I used to install them all the time when I did RV work. In this day and age, this is really pretty simple technology..you can get them in many different amp configurations, and yes, they do work.

You might check your owners manual, many trucks with towing packages have had them installed from the factory for many years now..even if you don't, installing an aftermarket unit will allow all normal functions without the trailer plugged in, the only time it comes into play is when it senses the second load of the trailer, other than that, you vehicle functions just like it was not there at all.

Yea my truck does not have anyithing installed. I know for a fact that my trailer plug remains live all the time.

I've used isolators before on other trucks but always with 2 batteries, one battery to each output, and the input of the isolator to the charging post of the alternator.

The more I'm thinking about it, I'm thinking a VSR inline in the trailer wiring is prolly the best option. It will allow the batteries to be separated while the engine is off, then after the engine starts, and the electrical system in the truck stabilizes they will reconnect and charge accordingly.





Bill

 

[MTboatguy]

Re: isolating truck battery, from trailer battery except to charge

Bill,

Your doing the exact same thing with the trailer, you basically have two batteries coming off one charging source, if you familiar with a truck and two batteries, then you will have no problem with a truck and a trailer with one battery each, it is essentially the same thing..instead of two batteries in the truck, you have one in the truck and one on the trailer..and it would be wired exactly the same way as the truck with two batteries in it. The only difference is you have a longer run of the correct sized wire to the battery on the trailer.

 

[Splat]

Re: isolating truck battery, from trailer battery except to charge

Bill,

Your doing the exact same thing with the trailer, you basically have two batteries coming off one charging source, if you familiar with a truck and two batteries, then you will have no problem with a truck and a trailer with one battery each, it is essentially the same thing..instead of two batteries in the truck, you have one in the truck and one on the trailer..and it would be wired exactly the same way as the truck with two batteries in it. The only difference is you have a longer run of the correct sized wire to the battery on the trailer.

Ok, then were all on the same page. I just wanted to make sure it would work correctly. Thanks for double checking me.

Bill

 

[Splat]

Re: isolating truck battery, from trailer battery except to charge

Another thing to check, does the charging system of the truck put out enough to charge your trailer battery?

However, if you connect the trailer to 110vac, didn't you say it charges your trailer battery? Then why do you need to charge it going home? Or, did I misunderstand?

I guess I was really interested in seeing pics of your trailer, as I too fly R/C planes and helis. Gonna need a trailer myself, eventually. Planes keep getting bigger, and hauling too much equipment.

EJ

Yes I have a inverter in the trailer too to charge off 110v. The trailer gets used for more than just the RC Stuff. I also use it as a impromptu camper when were out 4 wheeling. I would just like to be able the option to easily charge the trailer battery off the truck should we be out camping somewhere away from 110v, and start running low on battery juice. Thats all. I'm admittedly making it more complicated than it really needs to be, but it's how I want it setup.

I have the interior all torn apart on the trailer at the moment. I've been slowly building the interior to suit my needs this winter. I'll post pics when I get it done. In the meantime if you check out the guys over at FlyingGiants.com there is a whole thread dedicated to trailer setup.
http://www.flyinggiants.com/forums/showthread.php?t=5874

I'm going for something like the trailer pictured here, with less bling, but my rear work table will be fold-able so it can easily used for hauling cargo and 4 wheelers. I'm also going to have drawers up front under the front workbench, and LOTS of e track on the walls for securing cargo, also to hold the table mounts, and for supports for the bed while camping. Its a little bit of a project, but should be nice when it's done.

http://www.flyinggiants.com/forums/showpost.php?p=1406288&postcount=2247

Bill

 

[bruceb58]

Re: isolating truck battery, from trailer battery except to charge

Buy one of these:

http://bluesea.com/category/2/productline/overview/387

Put in an automatic resetting circuitbreaker to protect the wiring on your truck so that if the battery is really low and the current goes up beyond the current carrying capabilities of your truck wiring, the circuit breaker will toggle a few times until the current drops to a steady state level.

 

[Splat]

Re: isolating truck battery, from trailer battery except to charge

Buy one of these:

http://bluesea.com/category/2/productline/overview/387

Put in an automatic resetting circuitbreaker to protect the wiring on your truck so that if the battery is really low and the current goes up beyond the current carrying capabilities of your truck wiring, the circuit breaker will toggle a few times until the current drops to a steady state level.

Thanks Bruce. Those are what I started looking at last night. I agree it's the best option. I really like that one with the ability to have a contact position indicator in the cab of the truck.

Bill

 

[EJ42955]

Re: isolating truck battery, from trailer battery except to charge

... if you check out the guys over at FlyingGiants.com there is a whole thread dedicated to trailer setup.
http://www.flyinggiants.com/forums/showthread.php?t=5874

Bill

I'm familiar with the Flying Giants. I was able to attend the Tucson Aerobatic Shootout, back in '07. That was a good time.

Good luck with your trailer build,
EJ