Recharging boat battery's while towing....

C

Casey

New member
Can someone please tell me the easiest way to recharge my boat batteries while towing down the road?

I suspect it would involve a wire run from the back of the truck all-the-way back to the batteries, and a regulator to prevent the truck battery from discharging while 'boaterhoming.

...just not too sure if there's an "easy" way to do it!

Thanks,
Casey
 
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Casey,

I put this fitting on the port side of the TomCat. The wire inside goes to the battery bank. The outside wire is connected through the 7 pin RV type plug to the trucks hot charging pin. It's only hot when the truck ignition is on. Uses the truck voltage regulator.

IM000056.sized.jpg

The charging wire stays with the trailer when the boat is launched. I run the Norcold and the Waeco freezer while traveling down the road.

Brent
 
Thanks Brent,

That looks like a nice "clean" installation. Is there an "isolator" in the system somewhere (so you can't discharge the truck battery)?

Casey
 
My RV guy says to be sure to unplug the trailer plug when not running the truck to ASSURE that the truck battery will not drain down. Cheaper than more gadgets and wiring and more reliable. IF your memory still works okay such that you remember to unplug the thing.
 
On ours we put a 30 amp fuse on both ends of the wire. We started the circuit at the tow vehicle chassis battery, and went to the wiring harness. We then took a second set of #10 wire (covered with vinyl outer sheath, and a small two prong plug, on the trailer, up over the anchor roller, and into the anchor locker. There we attached it to a permanently mounted # 10 wire to the console, and directly to the positive bus bar. A 30 amp fuse on this end also. The segment between the trailer and the anchor locker could be unplugged easily--normally we disconnected this at night when camping in the boat. We did not have a diode, but that could be added near the vehicle battery. It will drop the charging voltage by about 0.5 volts.
 
We had a system simular to Dr. Bob's. We used a big Dodge van to pull our trailer boats and had a number 10 wire from the truck battery run inside the van. When we pulled over to sleep we just disconnected the wire that ran to the boat from inside the van and went to sleep. The reefer ran on the boat battery until morning and then we plugged in and down the road we went. Our connection inside the boat was just large battery clips. Crude , but it did work.
 
What are the makes/models/part numbers of what you used, Brent? Where are they available? I would LOVE to do this! Maybe this is a Gary Estes job on Daydream (sigh)...
 
I use 30 feet of #10 wire with a 7 prong at the camper (not the trailer) port in the truck bed and a 2 prong plug made for electric trolling motors at the C-Dory end. Purchased all at a local boat shop. I put the plug for the trolling motor in the housing by the house battery. I also unplug at night, just for safety. I like the two prong trolling motor plug as it keeps polarity right without thinking. I have the Norcold Refer and run some lights when using as a camper in Walmarts & etc. Holds the battery charge up fine.

I thought about making a shorter run by tapping into the trailer plug on the truck, but that would mean one more set of lines and plugs dealing with trailer lights. Things go wrong with trailer lights often enough, so I chose not to complicate them unnecessarily.
Chuck
 
Pat,

I don't have part numbers. I use the 7 pin RV plug on the back of the truck to plug in the boat trailer lights. It also contains a 12 volt hot lead. I wired the 12 volt lead to continue through the boat plug. Then about 12' of #10 wire to the trolling motor plug, which is under the port navigation light ( see the pic ). Inside the boat, the #10 wire continues to the port battery bank ( 3, group 27 batteries ). The port battery bank serves the Norcold Refer. and the Waeco Freezer. Also is the start for the port motor. In addition we have 90 watts of solar panels on the cabin roof. These are also connected to the port battery bank. The house battery bank ( 2, group 31 batteries ) is for everything else, plus starboard motor starting. Its separate from the port bank, but can be switched together if necessary.

We run the Norcold and Waeco 24/7. Last trip out ( British Columbia ) they ran for about 10 weeks continuous. As a last resort, we carry a Honda EU 2000. We used it on the Canada trip for a total of 2 hours. At Jennis bay, (no power ) after many days of clouds and rain with little motor running.

I bought the wire and plug fittings at Wefings in Florida. We were there in 2006 coming back from the Florida Keys and stopped to have some warranty work done on the Teleflex hydraulics. I did the wiring in their parking lot while we waited.

Brent
 
On late model Chevrolet pickup trucks, the auxillary pin is only hot when the truck is running - controlled by a relay which is turned on by the ignition key...
So charging the boat battery through this pin when running the truck will not allow the boat battery to discharge the truck battery when the truck engine is off..
I charge the battery for the power winch on my trailer through this pin and would use this to keep the boat set charged if I needed it..
On my 08 and 011 trucks with the flat 7 plug, when you open the spring oladed cover on the bumper and look at the plug, the pin #4 which is at the 1 oclock position as you look at the bumper is the Auxillary pin...
BTW, flat 7 means the 7 pins are flat, not the plug (which is round)

denny-o
 
I good solar panel or two providing at least 15 watt but 30+ would be better could be flat mounted on the roof sides and wired to the batteries with a small charge controller and this would keep you topped of when towing (dayime) but also work great out on the water. We run a 30watt panel on the water and it works so well I can't imagine not having it.
 
OK, I have a 7 pin socket on the Titan but my trailer has a flat 4 pin plug, and so is connected through a flat 4 to 7 pin adapter. I guess I don't see how to access the power on the pin in the 7 pin socket. Maybe Gary Estes could replace the flat 4 pin plug with a 7 pin plug and give me the hot charging wire to run to a trolling motor socket (ground just comes off the trailer frame?).

This is just for charging the boat batteries from the truck alternator while going down the highway, solar is a whole 'nother thing! Here I am looking to have enough power to stay at an anchorage more or less indefinitely. I am definitely going to have 4 x 30 watt panels, two on each side below the rails, since I need to put a dinghy or the kayaks on top of the roof. The polycrystalline 30 watt panels look like they are about $170 each, and a good controller, I think I can have ample power for those sunny climates for about $750. This would be supplemented by the outboard while running and the Honda 2000i if/when necessary. Patty isn't quite there yet but she will see the light eventually!
 
Pat it is very easy to convert the trailer wiring to the 7 pin round connector. Just look up trailer wiring diagrams on the internet, and the wires should be color coded. I would never use the trailer frame as ground--there is a separate (or should be) a separate ground wire. There is too much variable resistance relying on the ball hitch as a ground conductor. For example:
http://www.etrailer.com/faq-wiring.aspx
You also need to know this because there is a relay for the 12 volts in your truck:
http://www.titantalk.com/forums/titan-towing-hauling/29664-help-towing-breakers.html
 
Thanks, I will study this.

thataway":2uy46b8b said:
Pat it is very easy to convert the trailer wiring to the 7 pin round connector. Just look up trailer wiring diagrams on the internet, and the wires should be color coded. I would never use the trailer frame as ground--there is a separate (or should be) a separate ground wire. There is too much variable resistance relying on the ball hitch as a ground conductor. For example:
http://www.etrailer.com/faq-wiring.aspx
You also need to know this because there is a relay for the 12 volts in your truck:
http://www.titantalk.com/forums/titan-towing-hauling/29664-help-towing-breakers.html
Click to expand...
 
Pat - if you want, I could probably help you do this sometime in the not too distant future. It's on my list of things to do for the Tomcat (which already has the 7-pin plug but doesn't have the 12V wired yet). It's pretty easy to do.

Roger
 
Roger, that sounds like a plan! Let's figure out a good time!

rogerbum":2r4ze30f said:
Pat - if you want, I could probably help you do this sometime in the not too distant future. It's on my list of things to do for the Tomcat (which already has the 7-pin plug but doesn't have the 12V wired yet). It's pretty easy to do.

Roger
Click to expand...
 
This is a cool modification but even cooler, is the Ranger setup that not only charges the batteries on the boat but has turn signals built into the stern of the Ranger Tug! The whole shebang hooks into the trailer harness and lights up like a Christmas tree!!

Charlie
 
Update on boat battery (recharging while towing) project.

George (Kerri On) is here in the Verde Valley, so we've spent a lot of fun time working on stuff, solving the World's problems and even doing a few useful things - like the truck/boat wiring project.

The plug that Brent (Discovery) used is from WestMarine ( http://www.westmarine.com/webapp/wcs/st ... &langId=-1 ) and should work perfectly. (It's $18.49 @ WM.)

I opted to use #10 wire, George is using #12. I think #12 will work just fine, but my wire was already ordered, so I'll use it. Expensive ($1.72/ft) stuff!

The only wiring challenge so far was to find out why the "Battery/Aux" terminal on the 7-pin RV socket on the truck wasn't 'hot. George and I both have F150's and neither had a hot terminal; but they were dead for different reasons. As it turned out - the circuit has both a fuse relay + a 30A fuse. On George's truck there was a fuse, but no fuse relay. On my truck it just the opposite (fuse relay, but no fuse...). I suspect there are a couple FoMoCo assembly-line folks who are proud of the money they saved FoMoCo by not installing the necessary parts. (By the way, the new style fuse on F150's [the little square one] was $4.29 at AutoZone.) And that was for ONE fuse; 'spensive!

Anyway, I think we've solved the wiring 'challenges and later today we'll complete the job (as soon as it warms up a bit...22degrees last night).

George plans to do a temporary arrangement (one long extension-like charging cable from the truck to the boat battery) to make sure eveything works as planned before he drills a hole (for the WM plug) in the side of his new boat. Probably a good idea. I'll wait and see how it works.

As previously described the "Battery/Aux" pin on the 7-pin RV connection is ignition switch controlled and the power comes through the voltage regulator so we should be good-to-go.

Casey
 
Pat Anderson":c3qo79s6 said:
OK, I have a 7 pin socket on the Titan but my trailer has a flat 4 pin plug, and so is connected through a flat 4 to 7 pin adapter. I guess I don't see how to access the power on the pin in the 7 pin socket. Maybe Gary Estes could replace the flat 4 pin plug with a 7 pin plug and give me the hot charging wire to run to a trolling motor socket (ground just comes off the trailer frame?).

This is just for charging the boat batteries from the truck alternator while going down the highway, solar is a whole 'nother thing! Here I am looking to have enough power to stay at an anchorage more or less indefinitely. I am definitely going to have 4 x 30 watt panels, two on each side below the rails, since I need to put a dinghy or the kayaks on top of the roof. The polycrystalline 30 watt panels look like they are about $170 each, and a good controller, I think I can have ample power for those sunny climates for about $750. This would be supplemented by the outboard while running and the Honda 2000i if/when necessary. Patty isn't quite there yet but she will see the light eventually!
Click to expand...

Buy the ready made replacement 7 pin plug at 6 Robbers and run the wires you need. Trim and tape the rest. It is quick and easy.
 
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