Battery Charging While Towing

[DBBRanger]

I keep my R25 on a trailer and tow it to a cruising spot. The trip may be long (like 5nights/6days to the Keys) and therefore I really wish the truck would keep my batteries charged so that I can use the refrigerator and other power sources especially when 'camping' in the boat along the way. I've come up with a plan that I would love for all to critique.

I expect to make a pigtail that stores in the chain locker that is connected to the windlass positive and negative terminals. When power from the truck is available, I will turn on the rotary switch for the thruster/windlass. Thus the power will track 'backwards' from the windlass, through the switch and to the thruster/windlass buss bar. Here it will charge the thruster/windlass battery until the automatic relays kick in and combine the thruster/battery bank to the house bank and the starting battery bank (that's the way mine is wired - others may be different). This way, I don't have to run separate wires from the battery to the bow. The downside I see is that I have to have the rotary switch for the thruster/windlass turned on and therefore there is power to the windlass. I have read of numerous(?) reports of runaway windlasses so that would be a problem if it occured traveling down the road. To ensure that doesn't happen, I'll remove the chain from the gypsy in case the windlass does start up. Of course I have a line holding the anchor!

My Ranger is not available to me at the monment but I assume I can get to the terminals on the windlass from the chain locker.

I have wired the truck with a 10ga wire from the front to a connector at the back where a separate line will plug into and then plug into the pigtail on the boat. The 10ga wire goes to a solenoid that is controlled by a switch in the cab of the truck (I like to control when it is charging otherwise when it is plugged in, the truck battery will be immediately charging the boat battery even if the truck is not going). I've got a 30amp circuit breaker connecting the solenoid to the battery and a fuse on the line going to the switch in the cab.



Does anyone see a problem with this design?

Thanks,

Doug

 

[joempo]

I'm sure others will weigh in on this discussion. I'll leave comments regarding the electrical connection to the windlass to others. Here are my initial thoughts about your truck.
Regarding the truck connection and concerns about battery discharge, I would consult with a shop that deals with towing RVs. I know the house battery in my 5th wheel is charged by my truck's charging system and is connected whenever the trailer is connected to the truck (running or not). My truck has an automatic electrical fail-safe that prevents the truck battery from discharging below a pre-set level if the 5th-wheel battery is drained. In other words, the truck battery will not drain to the point of being unable to start the truck.
If your truck is wired for towing and has the large round, seven connector receptacle, power is already available full-time. That same RV shop should be able to assist you in modifying a plug and wiring your boat's pre-existing pigtail for a charging circuit.
Good luck with this project. I'll be interested in your final resolution, since we are also interested in trailering long distance.

 

[DBBRanger]

My truck has an automatic electrical fail-safe that prevents the truck battery from discharging below a pre-set level if the 5th-wheel battery is drained. In other words, the truck battery will not drain to the point of being unable to start the truck.
If your truck is wired for towing and has the large round, seven connector receptacle, power is already available full-time.

Thanks for your reply. I'm not good with automatic things - I prefer to be in control, so that's why I'll make sure the truck is at speed before I turn the charging on. I'm aware that there is power to the 7 conductor receptacle, but I didn't think the wires running to it were large enough to support a good current. Hence the installation of the 10ga. Also, I'm using a set of battery cables modified with connectors on the ends to get from the truck to the pigtail on the boat. I'll let you know how it works! I'm still crossing my fingers, hoping I can make a connection at the windlass!

Thanks again

Doug

 

[DBBRanger]

It doesn't work!!

My wiring diagrams for the R25 only show "see Windlass Diagrams" but I don't have those diagrams. I assumed they were like the thruster diagram that shows the power lines going directly to the thrusters - I assumed the windlass was the same and therefore I could connect the power from the truck to the windlass and from there to the batteries. Bad assumption -especially bad since it took me 3 hours to drive to the boat to find out that isn't correct. It turns out the power wires to the windlass are only hot when the windlass is operating. There is a switch behind the helm that switches on the power to the windlass when the control buttons are pressed. So my hope of not having to run wires back to the house batteries from the chain locker was dashed.

Not only that, but also the wires go directly to the inside of the windlass motor - no connectors. I hope I never have to take the windlass out!

So, has anyone routed wires from the chain locker back to the batteries? How was it done?

I'm back to square one except now I have nice wires in the truck and a nice extension cord that goes to the bow but no place to go after that!

 

[Levitation]

Fish a pair of 10 ga wires from the engine start battery going forward.
The starboard side is the best route on a 25 - past the water heater into the shower (sink cabinet) then to the helm, then put a bulkhead connector to the outside near the shore power, or find a route into the chain locker.
Connect the wires to the engine battery because that is the control point for the ACR relays.
When the engine start battery sees 13.6-13.8 volts applied from the truck ACRs will close and charge the entire battery set.
It will take less time than you spent driving just to look at it.

 

[Irish Mist]

I really don't know what I'm talking about here but I had a thought... What if you used your new heavy wires running from your battery to power an inverter. Then just run your shore power cord to the back of the truck for your trips.. That way no mods needed ... Like I said I don't know what I'm talking about just thinking out loud .

 

[knotflying]

It doesn't work!!

My wiring diagrams for the R25 only show "see Windlass Diagrams" but I don't have those diagrams. I assumed they were like the thruster diagram that shows the power lines going directly to the thrusters - I assumed the windlass was the same and therefore I could connect the power from the truck to the windlass and from there to the batteries. Bad assumption -especially bad since it took me 3 hours to drive to the boat to find out that isn't correct. It turns out the power wires to the windlass are only hot when the windlass is operating. There is a switch behind the helm that switches on the power to the windlass when the control buttons are pressed. So my hope of not having to run wires back to the house batteries from the chain locker was dashed.

Not only that, but also the wires go directly to the inside of the windlass motor - no connectors. I hope I never have to take the windlass out!

Here is what I am thinking, If you install some type of A/B switch (A for windless, B for batteries) before the windless switch then that would isolate the windless operation. Then run a lead from the B side to the chain locker. Another thought I had was since I own a Honda 2000. Just sit it in the cockpit while driving, plug in the shore power, secure the generator and drive on.

So, has anyone routed wires from the chain locker back to the batteries? How was it done?

I'm back to square one except now I have nice wires in the truck and a nice extension cord that goes to the bow but no place to go after that!

 

[walldog]

I really don't know what I'm talking about here but I had a thought... What if you used your new heavy wires running from your battery to power an inverter. Then just run your shore power cord to the back of the truck for your trips.. That way no mods needed ... Like I said I don't know what I'm talking about just thinking out loud .

At first this seems like a logical solution, However. It is not a good idea to plug your boat into an inverter. It will cause problems with the inverter you use and the charger/inverter on your boat will not like what it sees coming down the power line. Chargers do not play well with non syne wave power. Do not ask me how I know. Best case you will fry two inverters. Cheaper and more efficient to run wires to the engine battery as described previously by Levitation.

 

[Irish Mist]

Like I said 🙂 Thanks for the clarification.. The other thing is If it is just for when you are towing.. Maybe make some sort of connection where it is easy and just run a cable along the boat when towing... Would save trying to do a lot of fishing and wire hiding.. You were going to run a cable from the anchor locker anyways.. Just make it longer .

 

[DBBRanger]

Mike,
Did you have something to say? I couldn't hear it!!

Doug

 

[knotflying]

Sorry about that. My response was, I am thinking that you can put an A/B switch in before the windless switch, A for windless and B for Battery. Then run a lead from the B side to the windless compartment for the battery connection. The other thought was that since I have a Honda 2000 just secure it in the cockpit, plug in shore power and then let her run while on the road.

 

[joempo]

Based upon Levitation's suggestion/information, perhaps the incorporation of a truck-to-boat charging circuit would be another improvement for Ranger Tug to add to future boats, particularly the 21, 25 and 27 since they are the most trailer-friendly models. Perhaps I'll take a look to see how difficult it would be to add a #10 wire for charging, replacing the ground with a #10 and changing out the flat connector with a round "RV" connector to plug into the truck.

 

[knotflying]

Not a bad suggestion. They are touted as a trailerable cruiser and they did go through the trouble with the special wiring for lights while trailering. Perhaps very practical charging connection is the best use of time and energy during construction.

 

[Osprey]

I spent a number of years towing a fifth wheel trailer. My experience has been that the battery charging during towing is moderate at best. That is, if I broke camp after an overnight off the grid and then towed most of the day, the trailer batteries would not be fully charged by the end of the towing . Generally I had to complete charging using a Honda generator. However, if the main objective is just enough charging to supply the refrigerator, then charging when towing might be okay. However, for towing my Ranger, I find that a solar panel supplies more than enough energy to run the refrigerator.
That said, lets get back to main question of this tread, "How to arrange to charge when towing". DBBRanger hoped to make a connection via the windlass circuit. To do so he would need access to the hot side (+12V) of one of the three switches which control the windlass operation. As pointed out earlier in this thread, the switch located at the helm station is one location. The other two switches are the up and down "foot switches" located on the deck next to the windlass. I have never stuck my head into the anchor locker to see how practical access is to these switches. However, access must be possible in that these switches will need replacement sooner or later.
Supposing a connection as described above is practical, the next consideration is "Which battery or batteries will be charged?" Well, of course, in the first stage, the thruster/windlass battery (for an R-27 and I expect most other R-## models) would receive the charging current. On my R-27 the thruster/windlass battery is linked to the starter battery via an ACR, so once the thruster battery voltage reached the ACR activation threshold, the starter battery would also receive charging current. Finally the starter battery is linked to the house bank by a second ACR, so provided that the starter battery voltage was sufficient, second ACR would close and the house batteries would also receive part of the charging current. With all these batteries on line, the charging of the house set is going to be a slow process.
If I were tempted to charge while towing I would follow the suggestion by Irish Mist.

 

[DBBRanger]

I should have searched this forum again to remind myself that there is a relay behind the helm. I wouldn't have been so quick to make my 3 hour trip.

Thanks for all the ideas!

Maybe make some sort of connection where it is easy and just run a cable along the boat when towing

That's what my wife wants me to do.......but I feel the need to overengineer it (as she would say!)

I have a Honda 2000 just secure it in the cockpit, plug in shore power and then let her run while on the road

Same as above! I just hate the idea of having all that power available from the truck and not using it though.

put a bulkhead connector to the outside near the shore power

That sounds good - at least it's closer than going all the way back to the batteries

.....towed most of the day, the trailer batteries would not be fully charged by the end of the towing

Boy, that's surprising and disheartening!

"foot switches" located on the deck next to the windlass

I don't have the schematics, but I would expect the wires at the foot switches to go back to the switch at the helm and therefore are control wires, not high power wires

On my R-27 the thruster/windlass battery is linked to the starter battery via an ACR

On mine, the thruster battery links through an ACR to the house and through the other ACR to the starter so my wiring is more ideal. Plus, I don't expect the thruster battery to be discharged so the ACR may quickly switch on

I mispoke in my original post - I actually used 8ga from the battery to the back of the truck. Also used 8ga for the jumper from truck to boat. I'm wondering if 10ga in the boat for the 25' needed would be enough. There is 10ga at the windlass, but I believe it's 8ga going to the switch at the helm from the battery. Come to think of it, it looked to me like it was 8ga coming off the switch at the helm. Maybe that goes somplace else before going to the windlass - maybe going to the thruster first? Does anyone have the schematic for an R25 thruster and windlass? I hate not having the boat in my backyard!

Thanks again for all your help.

Doug

 

[knotflying]

I actually think over engineering things is in our blood. I have been towing my boat since new and with the solar panel have always been fine. Usually at night I am at a campground and plugged in and charging up. While on the hook I have gone 3 days and I have been fine. So trailering for three days without a charge is the same. Now I did join my thruster and house batteries so I get more amp hours. And I put a switch between them so I can still isolate the thruster if needed. So the thought of coupling the truck to the batteries is nice, but is it really necessary?

 

[JamesTXSD]

Some of this does sound like over-engineering. For our C-Dory 25, I ran a 10 gauge wire from the second 7-pin connector on our truck (for towing our 5th wheel); ran it along the trailer, then up the stern of the boat and directly to the house batteries. I put a fuse in the line, before the batteries. It ran the fridge and kept the batteries topped off while driving during the day. We generally stayed at RV parks while towing to a distant location, and plugged in at the park overnight.

When it was time to launch, it took a minute or two to unhook the wire and put it away before dunking the trailer. Easy; effective.

Jim B.

 

[DBBRanger]

I ran a 10 gauge wire from the second 7-pin connector on our truck (for towing our 5th wheel); ran it along the trailer, then up the stern of the boat and directly to the house batteries.

I kind of like that, but did the connector to the batteries get dunked when launching/retrieving the boat or do you mean you rolled up the wire and put it in the truck?

 

[JamesTXSD]

I ran a 10 gauge wire from the second 7-pin connector on our truck (for towing our 5th wheel); ran it along the trailer, then up the stern of the boat and directly to the house batteries.

I kind of like that, but did the connector to the batteries get dunked when launching/retrieving the boat or do you mean you rolled up the wire and put it in the truck?

Disconnected, rolled up, put with the trailer straps before launching.

 

[DBBRanger]

Well, here's what I did. As mentioned above, 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 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.

I'm happy!