Recharging boat battery's while towing....

rogerbum · Posted: Thu Sep 15, 2011 2:21 pm Post subject:

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

Pat Anderson · Posted: Thu Sep 15, 2011 2:23 pm Post subject:

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

Captains Cat · Posted: Thu Sep 15, 2011 4:33 pm Post subject:

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

Casey · Posted: Thu Nov 03, 2011 12:17 pm Post subject:

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/stores/servlet/ProductDisplay?catalogId=10001&storeId=11151&partNumber=181867&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

T.R. Bauer · Posted: Thu Nov 03, 2011 10:31 pm Post subject:

Casey · Posted: Wed Nov 30, 2011 7:34 am Post subject:

George (Kerri On) is back on the road after a great visit here in Arizona. We finished making the "charging cables" for both Kerri On and Katmai, and George reports that his cable is working very well,and makes "boaterhoming" easier, and one battery is conveniently recharged while the boat is on the trailer.

As it turned-out we both have Ford F150 trucks. Both trucks have towing packages so are fit with both a 4-flat connector for a trailer as well as a round 7 connector RV-type plug.

George used #12 wire for his cable, since I already had #10 cable I chose to use it. #12 cable is sufficient, and somewhat easier to work with. If I was to redo the cable I'd use #12.

Both George and I had previously installed fused 12v sockets in the cockpit to power a small fan/light/laptop. Those 12v sockets are wired directly to one or both battery's (not through the Perko switch). The boat-end of the cable simply has a "male" 12v plug which connects to a 12v socket, and recharges the selected battery. The truck end of the cable uses a round connector which is only connected to the switched auxiliary connector, plus the ground. The trailer lights/turn signal wiring is completely separate.

That's the quick version of our project. There were a few changes of direction, and a couple of discovery's in both truck's wiring/fusing systems, a few blown fuses, and one errant 3/4" hole drilled in Katmai, but it finally worked out well. The lesson we learned is to rethink an original plan, an go with the simplest option available! I'll save the full version of the charging cable story for a campfire story somewhere/sometime.... With enough wine, it would be pretty humorous.

Casey
Lake Montezuma,AZ

hardee · Posted: Mon Jan 04, 2016 9:53 pm Post subject:

Bringing this back for review. I'm interested in doing something like this. It makes for boaterhoming in comfort and practical --> you can use the boat's electrical store the same as you could if you were on the water.

I'm not interested in drilling a hole into my hull; I have a perfectly good hawse pipe on the fore deck that I will run the power supply cord into the cabin through. I have a 12VDC "cig" plug outlet that is live to at least one battery (I have 2 group 29's) even when the 1-2-Both-Off switch is in the "Off" position. I'm not sure I can charge both batteries through that plug (at all), or if I can do it with the switch in the "Off" or "Both" positions.

Wanted to bring this back and see if there are others who have done it and particularly anyone towing with a Tundra, just in case.

Harvey
SleepyC Moon

DBBRanger · Posted: Tue Jan 05, 2016 12:14 am Post subject:

I thought about this for a long time for my Ranger R25. I wanted it to be easy but be a quality installation and not cost an arm and a leg. The batteries on an R25 are in the aft so it's a long haul back there with decent size wires. My final installation doesn't perfectly match my desires as listed above, but is a good compromise.

I installed a 8-10GA wire from the truck battery to a 30A circuit breaker to a solenoid switch controlled by a switch in the truck cab and then to the truck rear end where I installed a male 30A 110V Marine connector. I then use my standard shore power cable and connect it to the connector on the truck. The shore power cable then runs along the topsides of the boat to the aft where I installed a pigtail with a female shore power connector and then another 30A circuit breaker and then to the house battery terminal block. When I'm running down the road, I flip the switch in the cab and charge the boat battery, but when I stop the truck engine, I flip the switch off in order to not charge the boat battery at the expense of the truck battery. This has worked to keep up with the load due to the refrigerator as I wished, however, it only charges at about a 5A rate so it will not bring up a severely discharged boat battery. The round trip length of the wires is more than 120' so the resistance of the wires plus the connector resistance tend to limit the current. I had worried that there might be too much current, but that didn't happen.

Some may be concerned that a 120V cable designed for shore power is being used for a 12V connection and that if the cable was mistakenly connected to shore power, I'd have big problems. That's a concern, but I've labeled them hopefully to insure that doesn't happen. The dual purpose cord helped keep the cost down. The 2 circuit breakers help protect both the boat battery and the truck battery.

My truck is a Duramax Chevy Diesel (2 batteries).

I wish I could get a higher charge rate, but I think that would take larger gauge cables (meaning big bucks!).

Hope that helps!

Doug

Aurelia · Posted: Tue Jan 05, 2016 12:27 am Post subject:

I don't have the need currently but a freezer installation this winter may change that (we can only make educated guesses at this point). I would personally look at using one of these:

http://www.yandina.com/c100InfoR3.htm

Combined with Dougs extension cord idea to have a simple and voltage regulated connection that I could connect and forget to keep the tow vehicle battery protected and charging active only when surplus power is available.

I would also not install anything to start with and test it to run simply from 12v socket in the cargo area of the tow vehicle to 12v socket on the boat. Think about what you are running and what the likely draw would be. For us is would be a freezer pulling .5-3amps so not much.

Greg

Two Bears · Posted: Tue Jan 05, 2016 1:08 am Post subject:

I replied to the first post in 2011 and have used that system since and it has worked well. In 4 years and more than 30,000 miles the only problem has been "operator error." Some thoughts after reading thoughts & comments above.
* I used a two prong Minn Kota plug designed for trolling motors. The plug will only go one way so no chance of changing polarity from a minute's inattention. Also, you need large wires to carry the power in a longer run like the 30 feet of wire I purchased. I used 10 gauge. My inlet receptacle is near the house battery at the back of the boat. I just googled "trolling motor plug" and the male/ female combo is less than $20.
* I visited with the mechanic at the Chev garage when setting it up. His comment was that having another battery just makes the car alternator think the new battery is part of the system and will bring it up to full charge. "Nothing special" was his implication. I was assured the truck system would shut off automatically. However, my last truck failed to turn off at least twice in 400+ nights with my camper. So I unplug when we are spending the night. As the wire runs from the Camper outlet in the side panel on the drivers side just behind the cab over the tail gate and then to the bow of the boat, I can't step over the hitch without getting my neck in the wire so I don't forget it. I have, however, forgotten to "replug" in the morning.

Chuck

hardee · Posted: Tue Jan 05, 2016 2:56 pm Post subject:

For measuring the wire run for a #12 wire, am I right in thinking that lenget will be from the 7 pin plug at the back of the pickup to where it would plug into the Cig lighter plug at the help, where I am thinking I can plug this into charge the boat batteries. I am also thinking I can leave my 1-2-Off-Both switch in the "Both" position to charge both batteries equally.

Harvey
SleepyC Moon

Will-C

Maybe it's just me, but the idea of a solar panel with a controller would seem like a better option for us anyway. That way you can always reap the benefits. We travel on land we usually use campgrounds that have power available so like with shore power the battery charger can replace what the batteries lost during the eight or ten hours of driving per day. Then you still have the solar panel working for you if your out on the hook. I guess most of this need for constant charging is a result of refrigerator / freezers? We usually work out of a cooler while on the road and then once the boat gets back in the water we turn on the refrigerator/freezer. We always have at least one cooler on the boat anyway. Our fish guests need a place to chill out till I get a chance to clean them.
D.D.

rogerbum · Posted: Tue Jan 05, 2016 3:56 pm Post subject:

hardee · Posted: Tue Jan 05, 2016 5:02 pm Post subject:

hardee