Car Hauler With LQ - 12V Electrical Upgrade - Help Needed

[dunk_0]

Hello Everyone,

I've a bit of a lurker here for the last year, using this forum as a technical database anytime I have problems with the 'rv' parts of my enclosed car trailer. It's been a great resource.

I wasn't quite sure where to put this thread, since I don't own an RV, but hopefully this is adequate.

I have a 36 foot gooseneck enclosed car trailer with the front 16 feet as living quarters. I've been having some issues with the 12v electrical system, and after reading some of the threads on this forum, I think I'd like to redo it completely. I'll explain what I have now below, and my thoughts for what I'd like. I bought this trailer used, and don't know its' complete history.

Currently there's two 12v deep cycle 'marine' batteries in the trailer. One is in the front of trailer, and hooked to the hydraulic motor for the front landing gear. It's also hooked to an inverter I installed and the 12 volt lighting circuits and the 12v water pump.

The rear battery is hooked up directly to small winch (2000 lb), an Onan 7000w generator, and also connected to the front battery with a 6awg cable.

There's also a battery charger connected to each battery. The front charger is a 2amp max battery maintainer, but the rear battery has a 10 amp charger on it.

The inverter I mentioned in the front was installed by me. We often go to racetracks where there's no shore power and we can't run the generator at night. We can heat the trailer with a small propane heater but need the inverter to run the fridge and an outlet to charge cell phones, etc...

What I'd like to do is remove the existing batteries (they're bad anyways), and replace them with four 6v batteries, which I would locate in the front of the trailer all together. I'm a decent fabricator, and there's plenty of room to build a nice battery rack up there and weld it in. If I do this I'm wondering what the best thing to do about the charging side would be.

Should I be looking to install a charger/converter for when the trailer's hooked up to shore power or the generator is running? If I put a converter in, will be there be any issues running the high amp equipment when it's plugged in, like the winch and the landing gear?

Any help or advise given would be really appreciated. I'll post up pictures of the work as I go along if people would like that.

thanks in advance,

Duncan

[dunk_0]

Got everything completed today. Here's some pictures of the setup. It was tight, but everything fit.

Upper tray.

IMAG0359 by duncanrellis, on Flickr

Lower tray.

IMAG0358 by duncanrellis, on Flickr

Inverter and transfer switch.

IMAG0362 by duncanrellis, on Flickr

Duncan

[hmknightnc]

The Progressive Dynamics brand of converter seems to be very popular with this group

Best Converters Website

[dunk_0]

Built some battery hold downs today. One will go above on the shelf where the existing battery is, and the other one will go down below. There will be less than 24" of cable between the two racks.


IMAG0354 by duncanrellis, on Flickr

Any recommendations on a good converter so I can get that ordered and a mount fabricated?

thanks,

Duncan

[hmknightnc]

dunk_0 wrote:


For hmknightbc, why do you saw to leave a 12v battery in the rear?

Since it is already there i would keep it. And generally 12v batterys are better for high amp applications so let it carry the high surge current for operating the winch and door. Buy a automatic battery isolator and install in the existing 6awg wire going to the rear battery. That way the converter will charge that 12 volt when it is operating and 12volt will be isolated from the 6volt bank when not charging (prevents the different type batteries from interacting with each other)

[dunk_0]

Thanks for the advice.

I'm absolutely sure there's no converter already installed in the trailer. When we're at the track, the only thing we really use the 12v system for during the day is the water pump. There are separate 115v lights (LED's up front, large fluorescents in the garage).

For hmknightbc, why do you saw to leave a 12v battery in the rear?

I bought a single 6v battery today which I'm going to use to mock up the racks.

thanks,

Duncan

[hmknightnc]

upgrading to 4 6volts sounds like the right idea for your use. I'm surprised a living quarters race trailer with 12 volt systems (lights and water pump) doesn't already have a converter so you might want to look around and see if it is already there and working

If I were you with long of a trailer and its use do the following
- Install the 4 6volt batteries as you propose
- Find and fix the existing converter or install a new one
- Keep the 12v in the back to operating the winch and door but use an automatic battery isolator to seperate the 6volt bank from it when not charging via generator or shore power

[westend]

There should be no problem using a standard RV converter/charger and I would think a bigger one would be the best choice, something bigger than 60 amps. That will allow for a quick recharge to 90% of capacity.
The winch and landing gear will be using the reserve power of the batteries along with assisted converter power if converter is powered with AC. No problems but remember to fuse wires correctly and use big wire.