Keeping a battery on a trailer charged

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I did not use an isolator since I seldom use the trailer while it is still hooked to the rig. When I get to my destination I unhook and go wheelin'. I did however use a self resetting breaker at the source to protect the circuit. The headlight harness and the trailer charge wire get their power straight off of the alternator instead of the battery since the voltage is a bit higher there. If I need to charge the camper batt I just hook up the cord and let the rig run for a while. To check the voltage I have one of those cheap Voltmeters that plug into a cigarette lighter.

I am resurecting this. I want to run a second battery in my trailer. I can pull out my 3rd brake controller out of my truck for battery charging purposes, but I really want to keep that in my truck since my camping trailer is only for my FJ40 and it is too small for electric brakes.

Is this what the self reseting breaker looks like if I want to run a line from the alternator to the quick connect on the trailer for chargning a battery? If so, I can "borrow" the one on my 3rd brake controller when I don't need it and use it in my cruiser.
breaker.webp
 
Me personally...I always ran 10# from the battery to a 30 amp breaker then to trailer hitch at the rear of the truck that would plug into another line that ran through the trailer to the battery location (note: always be sure to run a fresh ground to the trailer frame also) Personal preference was always a top of the line battery for both locations, and I never once came up short on power.

good luck,

pat
 
I have a similar system. Two 6 volt Trojan T105 golf cart batteries in series in the camper. 10 ga wire from the battery in the tow vehicle through a 30 amp fuse to the 7 pin receptacle on the bumper. 12 ga wire on the camper end of the 7 pin plug to another 30 amp fuse then to the batteries. I charge them up with a 3 stage battery charger before leaving the house, let the tow vehicle keep them charged while traveling, then, once at camp, disconnect the camper and enjoy camping.

Early in the morning I start the tow vehicle, connect the camper, and while the truck warms up, it helps top off the batteries from the nights draw down. The camper has 12VDC lights, water pump, and fan for the furnace. Sometimes I also use a 12v to 110V inverter to power the laptop for picture download from the digital camera. I also have a plug in the back of the tow vehicle that taps into this 10 ga wire. I built a harness with clips so I can strap down a smaller 12V battery in the rear cargo area and charge it during the day while sight seeing.

I have camped for as long as 10 days without hooking up the tow vehicle with this battery setup by being frugal with power usage.
 
I can't remember, do I still need an inline fuse if I use a 30 amp breaker?
 
I don't have a pic because that truck is gone...but I just came off the battery with about an 12" lead and mounted the fuse (or breaker) directly to the fender well...then took off to the back of the truck from there

Just a side note: try to keep all your wires together and zip tied so you don't have a pot of spaghetti under the truck :p

Autozone now has these cool as all hell things you put on your battery terminals that you connect blade connecters to..looks like a nice way to make a solid connection
 
I am resurecting this. I want to run a second battery in my trailer. I can pull out my 3rd brake controller out of my truck for battery charging purposes, but I really want to keep that in my truck since my camping trailer is only for my FJ40 and it is too small for electric brakes.

Is this what the self reseting breaker looks like if I want to run a line from the alternator to the quick connect on the trailer for chargning a battery? If so, I can "borrow" the one on my 3rd brake controller when I don't need it and use it in my cruiser.

That looks like the same type of breaker I used.
 
Hello,
For storage:
Battery Tender Junior Battey Tender 021-0123 $24.90
For camp:
Either Honda EU2000i or my mini Honda EX350 using the 12v tap to charge the batteries.
Hola
eric
P.S. Camping w/EU2000i:
Solar panels powering the van batteries during the day, EU2000 is right in front of the right front tire, small solar panel is powering the truck batteries, its a Solargizer pulse battery maintainer. While the generator is running the truck batteries are charged by a digital 24V 110V powered charger. Loosing a battery on a 15K truck 2 hours from the nearest auto parts store is not an option!

DSCN7368.jpg
 
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Solar Power = High tech
High Tech and Harbor Freight = :mad::doh:

Had one and it didn't work at all.

You need something that will cut off power when the battery is charged so you don't "cook it". Do you have a 12V converter on the trailer where you can plug it in to 120v power when available?

Yup sure do.
 

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