Charging while towing

[capnTelescope]

Disappointment was to find my Converter/charger is integrated with the panel.. Bummer.. This makes a change out to lithium a bit harder or should I say a bit more challenging.

Um, yeah. A shore-powered lithium charger will do half the job. The challenge comes from persuading the non-lithium panel charger to mind its own business and not try to charge the battery. This might not be possible, since the PD panel also wants to provide DC power to the 12V part of the trailer. PD's literature does not give me enough info to say with any certainty how to make that work. I'm sure that Progressive Dynamics would gladly sell you a lithium version of their panel. Some PD panels already come in two versions.

Oh, what the heck. It's only an extra couple hunnert bucks for a new panel. YOLO.

It's easy for me to say that when we're spending your money.

[RJ Howell]

Is the wire with the yellow insulator from the trailer battery? and the two together go to the TV and the panel?

The two together are the TV and TT battery, the yellow insulator is to the panel. Kinda silly how it's done. The pin connector comes in up front, where the is another auto breaker and a perfect spot to connect and not travel an additional 20ft (+-) to get back to the same spot near it's start.. Weird, but probably another industry standard..

The red 12v is the one you see on the left. It runs right by this fuse, yet doesn't touch it. That fuse receives the return lines and goes to the battery. This now leads me to believe the alternator 'is' fused to the TT battery. Tell ya, I'm learning by the minute here!

[capnTelescope]

My mind is boggled.

[RJ Howell]

My mind is boggled.

Yup! Mine as well.. Adult supervision would have helped when it got wired..

[capnTelescope]

Can you draw us a picture of which wires are going to/from where? Might help to un-boggle us.

[RJ Howell]

Can you draw us a picture of which wires are going to/from where? Might help to un-boggle us.

I'm heading out to verify (test) the wires and confirm my assumptions. I'll then do a flow-chart.

[RJ Howell]

Here we go.. Hopefully clearing up some of this mess they call wiring.. The only unconfirmed fusing is now from the TV. I will research this a bit more yet I believe that 12v feed comes through the TV's fuse box.. Now I can see that I'm 30a breaker protected between the TV battery and the TT battery aft of the 7 pin harness.

The second red in the return photo is my Solar plug on the rear of the trailer. I now know this is fused, cool!

[kmack67.km]

An inexpensive solar charger has been working for me, about 6 years now..
I have 2 medium size emergency light style AGM batteries. I only have a
few led lights and a stereo radio.

I just want to make sure I am following this correctly. Are you connecting the 12V aux supply from your tow vehicle to one of the solar charge controller inputs?

Best regards,
Kevin

[Tyrtill]

I've been pretty happy with my direct connection charging on mine. I pretty much have 4AWG wire run from the tow vehicle battery through a solenoid to a large connector and to the camper battery. With my clamp on meter I have seen 38A running through this connection when the camper battery was discharged to 12.0V. For the most part the alternator on the Honda puts out 14.3V at first and then drops to 14.1 and if I put no heavy loads such as headlights it will settle to 13.7V once both batteries are topped off. I worry a little that my little car battery may be overcharged but only time will tell. The AGM battery in the camper seems to be pretty happy and will be "fully" charged in about 1h30m on the road from 12.0V up to 13.7

Here is the underhood solenoid setup.

And these are the heavy gauge connectors. (There is also a normal 4 pin trailer connector)


This is the general overview.


I could have saved some money on wiring and actually had slightly less voltage drop if I just grounded the black wire to a trailer hitch bolt or something similar but I wanted to be able to transfer the $100 worth of wire to another vehicle easily in the future.

While on shore power I just use a cheap 8A Stanley Fatmax plugged into one of my "cigarette" dc outlets.

[Aguyfromohio]

I've been pretty happy with my direct connection charging on mine. I pretty much have 4AWG wire run from the tow vehicle battery through a solenoid to a large connector and to the camper battery.


Here is the underhood solenoid setup....

This is the general overview...

That's amazing Tyrtill.
We came up with the exact same kit of parts for our rigs - same 4 AWG wire, same solenoid, same connection points, even the exact same red colored Anderson connectors.
Our goal was not charging while towing, but running the air conditioner from the tow vehicle while boon docking.

[pchast]

An inexpensive solar charger has been working for me, about 6 years now..
I have 2 medium size emergency light style AGM batteries. I only have a
few led lights and a stereo radio.

I just want to make sure I am following this correctly. Are you connecting the 12V aux supply from your tow vehicle to one of the solar charge controller inputs?

Best regards,
Kevin

\
Yes

[Mark Gunter]

I realize that the last post was November of 2019, but I'm resurrecting this just because I'm wondering if Tyrtill ever got his planned inverter & A/C hookup, and if so, how well did that work? Also, Aguyfromohio was evidently already doing the same thing. Would love to know how well this has worked out, pros & cons, etc.

I run 300 watts solar with 2 100ah batteries (AGM). I have a 1kwatt inverter that is rarely used, only when really necessary. But the ability to run the A/C in the camper when boondocking would be a big deal, and this is the first I've heard of such a system of running A/C via tow vehicle ...

[tony.latham]

With my 2019 build, I installed a switch in the galley to turn the tow charge line on/off. I don't think an auto voltage regulator is ideal for deciding when and how much to charge an AGM in the camper and a starter battery under the hood at the same time.





The switch has been on once, and that was to test the voltage to make sure it worked. But yeah, I charge while towing. A 30-watt solar panel on the tongue box and a 100-watt panel on top.

Works like a champ.





Tony

[Mark Gunter]

With my 2019 build, I installed a switch in the galley to turn the tow charge line on/off. I don't think an auto voltage regulator is ideal for deciding when and how much to charge an AGM in the camper and a starter battery under the hood at the same time.





The switch has been on once, and that was to test the voltage to make sure it worked. But yeah, I charge while towing. A 30-watt solar panel on the tongue box and a 100-watt panel on top.

Works like a champ.





Tony

Awesome, Tony. Like you, I never really saw a need for the “charge while driving” when living in my van because my 300 watts of solar kept my batteries charged. But I never considered running an a/c via inverter with the tow vehicle as a power supply, as the last two posters suggested.

I mentioned the idea to my wife this morning and she reminded me that we can always run the little camper off our generator when boondocking if we need a/c, and of course she’s correct. I can’t really wrap my head around using the tow vehicle that way anyhow, it isn’t designed for that, so it seems to me that it would be a waste of vehicle fuel and a strain on a long-idling engine as well as on the alternator and the batteries (my F350 diesel has two vehicle batteries).

So I find myself back in the same camp this morning, vehicle charging seems to me unnecessary at this point, and I’m not sure the guy’s who were doing the a/c thing while boondocking are even still active here.

*And of course, by a/c I mean air conditioning, not AC alternating current. I’m already set for AC when needed.

[Tom&Shelly]

A solar panel on the roof of the tear works real well charging while towing it in the sunny West. Maybe not as much in the rainy East. Jus' sayen...

Tom