Trailer Power Question

[WickedZJ]

My wife and I have been talking lately about picking up a enclosed utility trailer to convert into a travel trailer. This trailer will not be taken on anything more difficult than fire roads, dirt roads, highway, etc unless I can figure out how to lift it a bit. The plan is to use it as a base camp to go exploring. It will also be taken to modern campgrounds (I know its a curse word) where they have power hook ups for rvs. I wanna be able to run the electrical off a couple house batteries but the times when we are at modern sites plug into the provided power.

My question is whats the best way to do this? Would running everything 12v with a large inverter ,for her amenities, with a in a marine charger that I can plug in work? or would running a dual ac/dc system?

 

[wrcsixeight]

If your wife's ameneties include a hair dryer, and she has a lot of hair, get your self a 2000 watt generator, because you will have a hard time trying to replace the amps consumed from the batteries Via an inverter.

It can be done without the generator, but the bank of batteries will need to be pretty large, and you will be replacing batteries fairly often.

Put the word' marine' in front of anything, is the same as doubling the price. Unless you are in a salt air saturated environment, 'marine' products are overpriced and overkill.

 

[WickedZJ]

Nah she can go with out a hair dryer lol but she wants a fridge, trying to convince her to get an Engel or other 12v fridge, a tv and dvd player so the kids can watch a movie before bed, a small heater and battery chargers for the camera, gps, radios and flashlights. Also the only reason I said marine charger was so its sealed.

 

[wrcsixeight]

Well then, 4 6volt golf cart batteries should give you enough capacity to go a couple days, and the inverter need not be all that big.

The heater must of course be propane powered. No electric heat via batteries. It is possible, but for very short periods only. Some propane heaters have 12v dc fans, which can be a significant battery draw too, depending on how long it runs.

Are you planning on putting the battery charger outside?

There are products called converters in the RV world which supply 12 volts for the devices and also will charge the batteries. These are good for when you are using 12 volt devices while trying to charge the batteries.
http://www.bestconverter.com/

Regular battery chargers can have a difficult time holding the correct charging voltage when there is a changing load on the batteries, like the cycling of a fridge's compressor.

If you need a lot of propane for heating, consider a 3 way absorption style fridge, which will be mostly powered by propane. (12 volts for the circuit board) These need dedicated ventilation so no byproducts of combustion enter the living space. They are also silent, where compressor fridges make some noise and vibration, like your residential fridge.

Whatever product you decide on as a charging source, get one capable of at least 40 amps, not only to faster recharge the batteries, but most batteries will actually need higher initial charging amps to perform best on the next discharge cycle.

The old and slow "trickle charge" mentality, In my opinion, is not effective at prolonging battery life. Replace the amps quickly when the battery is low, they will taper down as the battery gets closer to full and develops more resistance. The last 20% of charge can take many many hours so it is beneficial to get them to 80% as quick as possible, especially if you are using a generator to recharge the batteries.

 

[Mike S]

I have 4 six-volt AGM GC batteries in my 24' Airstream. I run a 6.8 CF (12V) fridge, heater blower, and lights without shore power. I can last about 4-5 days. I use a Honda 200i genset through a 4 stage converter to recharge or run 110 accessories.

I think this would be overkill in a utility trailer. In my old off-road trailer I ran the fridge, lights, water pump with 2 grp. 31 deep draw marine batteries and a dual 10 amp marine charger. Worked great. Just about everything you listed, including TV/video (but not a hair dryer) is available in 12V models.

 

[WickedZJ]

Why use GC batteries instead of say two Die Hard Platinums? The wife just told me she is not spending the same amount on a fridge as the trailer itself. Shes not real thrilled about a $1000 fridge. She is looking at $100 12v fridges or like a dorm room 120v fridge. She would also like to have a/c in the trailer so if we go out in 120 deg temps the trailer will be cool. I have seen a/c units that roof mount that might work.

As for the batteries and chargers I was thinking about a tongue box up front to mount them in otherwise I'll mount propane on the tongue and the batteries inside. Another thing I was thinking about down the line maybe a solar panel to help recharge them when away from a power source.

 

[wrcsixeight]

I recommended the GC batteries because they offer the most amp hours (capacity) per $$.

4 GC batteries will give you twice the capacity of 2 group 31 DHP's for significantly less $$$. The main advantage of AGM batteries are vibration resistance, Faster recharge times, maintenance free( no watering), and no outgassing unless severely overcharged. Why pay for what you do not need?

There is no way to feasibly run an air conditioner from batteries. You will likely need a generator capable of 2400 watts to do so.

It is certainly possible to run a conventional fridge on an inverter. Many people do it, but it is significantly less efficient to do so. Dorm style fridges are not designed to handle vehicular vibrations, and you might find that the door opened in transit and spilled your food all over the place.

 

[wrcsixeight]

She is looking at $100 12v fridges

These types of fridges can only cool to about 40 degrees below ambient temps, and will consume about 3 to 4 times as much power as a 1000$ 12 volt compressor fridge.

If they worked well, and were efficient, 1000$ fridges would not exist.

 

[WickedZJ]

Yea I think she get a fan and maybe a rooftop a/c unit that can get hooked up to shore power at a campground. I agree about the fridge although I may have to look into rv style fridges and see what I can find.

 

[wrcsixeight]

Try looking for a small travel trailer that already has what you want. By the time you find an empty utility trailer and convert it for your needs you could easily spend more money and have something less utilitarian, comfortable, and heavier.

If you need to modify something, give it some suspension.

 

[WickedZJ]

I have looked around at travel trailers and there isnt anything that isnt beat up for around 6k. I can buy a brand new 18' for 3-4k, get all the woodworking done for free, wire it myself, and so forth. I figure it would cost me about 6k in the end to build it which is why I was thinking about doing it.

 

[UNI]

WickedZJ Posted: My wife and I have been talking lately about picking up a enclosed utility trailer to convert into a travel trailer

A very good friend of ours, a member over on ORCC did exactly what your talking about doing.
His trailer turned out real nice, I thought I'd post his video, so you could get some ideas.

Hope this helps!

UNI
[ame="http://www.youtube.com/watch?v=ASKLopDLo9M"]YouTube - The BOONDOCKER - Cargo/Camping Trailer[/ame]

 

[WickedZJ]

Nice video. Looks like he has a good trailer. I need to figure a few more things out and get it sketched up