Upgrading TV to Scamp wiring

[Stretcher]

We are planning to drive our 2011 Scamp 5er from Massachusetts to Texas in late December and plan to spend at least three consecutive nights at Walmarts along the way. I’m concerned that with our existing wiring, the Group 24 battery won’t get enough charge from our Nissan Frontier alternator to use the heater enough.
We’ve installed LED lights throughout to reduce the drain and will install a ‘Charge Wizard’ on the ‘Inteli Power 9130’ to maximize the charge when plugged into AC. We will also install a ‘Trimetric TM2025RV’ with 100 amp shunt to monitor what is happening.
I am contemplating running #2 welding wire from the truck’s alternator to an 80 amp fuse to a battery relay and then back to a standard welding wire connector at the rear bumper. I would also run another length of welding wire from the engine block battery ground back to another connector at the bumper. The relay would be powered from the ignition circuit, and run through a toggle switch on the dashboard inside the truck, so power would only go to the coil of the relay when both the ignition was on and this new toggle switch was on. That way, when the engine was off, the relay would be open and there would be no power on the heavy cable, and I don't risk shorting it out when connecting and disconnecting. When the trailer batteries are fully charged, I can flip the toggle switch and stop the charging process. I’m led to believe that this would be better than using an isolator, which would cause some of the voltage drop that I’m trying to overcome.
Assuming the above is okay, can I connect the trailer side of the welding wire directly to the Scamp battery? Should I put a fuse in this end?
We may decide to include solar in the future, but unless it was attached, it wouldn’t solve the charging while traveling issue. While I like PeterH's setup, we have an AC, which would cast shadows on an installation modeled after his. We may pick up a small catalytic/propane heater on our trip, but they are illegal to sell in or ship into MA.
Thanks for taking the time to review this lengthy inquiry,
David

[Thomas G.]

I did basically what you have described, only I used #4 wire that I picked up at a metal recycler for about 10 cents on the dollar of retail. You will want a circuit breaker at both batteries.

I used an Anderson connector to hook the heavy cable to the trailer. I also ran a separate ground from the vehicle frame to the connector then back to the trailer battery.

http://www.grainger.com/Grainger/AND...onnector-3BY20

Much cheaper on eBay.

[floyd]

Originally Posted by Stretcher

We are planning to drive our 2011 Scamp 5er from Massachusetts to Texas in late December and plan to spend at least three consecutive nights at Walmarts along the way. I’m concerned that with our existing wiring, the Group 24 battery won’t get enough charge from our Nissan Frontier alternator to use the heater enough.
We’ve installed LED lights throughout to reduce the drain and will install a ‘Charge Wizard’ on the ‘Inteli Power 9130’ to maximize the charge when plugged into AC. We will also install a ‘Trimetric TM2025RV’ with 100 amp shunt to monitor what is happening.
I am contemplating running #2 welding wire from the truck’s alternator to an 80 amp fuse to a battery relay and then back to a standard welding wire connector at the rear bumper. I would also run another length of welding wire from the engine block battery ground back to another connector at the bumper. The relay would be powered from the ignition circuit, and run through a toggle switch on the dashboard inside the truck, so power would only go to the coil of the relay when both the ignition was on and this new toggle switch was on. That way, when the engine was off, the relay would be open and there would be no power on the heavy cable, and I don't risk shorting it out when connecting and disconnecting. When the trailer batteries are fully charged, I can flip the toggle switch and stop the charging process. I’m led to believe that this would be better than using an isolator, which would cause some of the voltage drop that I’m trying to overcome.
Assuming the above is okay, can I connect the trailer side of the welding wire directly to the Scamp battery? Should I put a fuse in this end?
We may decide to include solar in the future, but unless it was attached, it wouldn’t solve the charging while traveling issue. While I like PeterH's setup, we have an AC, which would cast shadows on an installation modeled after his. We may pick up a small catalytic/propane heater on our trip, but they are illegal to sell in or ship into MA.
Thanks for taking the time to review this lengthy inquiry,
David

We have made similar trips with a group 24 battery and also with a group 29 battery. Our charge wire is ten guage (if I recall)with a 30A breaker.
We also run a 400W trusine inverter and watch television and movies and use incandescent lights and water pumps with impunity. We have boondocked for as much as three days with no problems.
While traveling, the battery is fully charged each evening, even when running the fridge on 12V while driving (switched to propane at night when needed) A practice which we have abandoned in favor of frozen water bottles.
We use our propane furnace as needed, whenever it is cool out and we don't have shore power for the heatstrip in our A/C.
All of this is to say that you should do very well with a conventional set-up without the need for extraordinary measures.

[Stretcher]

Tom,

Do the Grainger connectors have a positive locking mechanism? It's hard to tell from their website. Does each connector handle a positive and a negative cable? If so, they would definitely be better than the individual welding wire connectors.

My son has access to used welding wire. It is pricey when buying it new. I'm led to believe it is pretty flexible, relative to its size.

Should I be using circuit breakers instead of fuses? If so, what size?

Thanks much,

David

[steve dunham]

The Anderson connector sold at Graingers is designed for two wires
(Pos & Neg ) and is used with electric forklifts and industrial battery chargers. A fuse provides more reliable protection than a breaker and is usually less expensive than a breaker . I agree with Floyd , I have never had a problem charging my 24F battery with the conventional method

[Carol H]

David, I headed down from BC to Arizona last December with only one deep cell group 27 battery and found that if I didnt run the fridge of DC while traveling only on propane at night that I could run the furnance prior to going to bed and in the mornings with no problem and leave it on the lowest setting at night while I was still in the colder climate areas and really needing it. Like Floyd I start out with a couple of frozen bottles of water in the fridge and I keep a couple of smaller freezer packs in the freezer which I use in the main fridge area while traveling and re freeze every night when the fridge is on propane. Thats all that was really needed while still in the cooler climate to keep the fridge down at a safe level providing it wasnt opened when not running. Sorry have no idea what the charge wire size is from the vechile but it did fully recharge the battery each travel day.

I think you will find as I did that having the LED's inside the trailer is a big help as far as how long you can go without power. Another item you may want to pack is a couple of small LED headlamps - they work well for reading at night while conserving trailer battery power for the furnance.

Have a great trip! Wish it was me this winter.

[Thomas G.]

Originally Posted by Stretcher

Tom,

Do the Grainger connectors have a positive locking mechanism? It's hard to tell from their website. Does each connector handle a positive and a negative cable? If so, they would definitely be better than the individual welding wire connectors.

It is semi-positive, I wrap a small bungee cord around the cable to keep it all tight. Read up on Anderson connectors, they are a very high quality way to connect large amp wires. Yes they are positive and negative.

My son has access to used welding wire. It is pricey when buying it new. I'm led to believe it is pretty flexible, relative to its size.

Should I be using circuit breakers instead of fuses? If so, what size?

Thanks much,

David

I prefer a 30 amp auto reset breaker so if there is a surge, I don't get to my destination and find out the fuse was blown and the battery didn't charge.

[Darrell in Al]

the connectors are secure I have them and use them on 3 winches, and I use welding cable for them.

V/R
D

[Stretcher]

Thanks to each of you that has taken the time to respond. I'll probably do the modification, as my wife sleeps better if she hears the furnace fan going on a few times each night.

David