RV Battery Charging From Trucks Alternator

[Mopar1973Man]

Just an update. We topped out at 81*F here outside. The RV is barely creeping up to 57*F inside. Very comfortable inside. Now if my solar was on the roof my batteries will be dead within 24 hours.

[Mopar1973Man]

Just another update. The sun is going down on the ridge and casting shadows in the yard. This point I've lost all charging solar for the house. It's done for the day. My solar controller shows 0.4 amps at 24 volts or 9.6 watts.

 

Edited April 17, 2016 by Mopar1973Man

[IBMobile]

Do you have room to comfortably carry portable solar panels in your truck camper when traveling?  In a 30' travel trailer there is room inside or in a basement compartment to store it but how much room in a cab over truck camper?

[Mopar1973Man]

Just now, IBMobile said:

Do you have room to comfortably carry portable solar panels in your truck camper when traveling?

 

Like mine fit under the bed. I know JAG1 has limited room being a slide in camper. This is the only thing I could find quick of JAG1 camper.

[JAG1]

My camper basement under the floor will store them fine being 5 ft. long and about 3 ft. wide. But its only 14 inches high and with bar-b-que and chairs I would have to jostle things around for storing the panels. I'll have to figure something out as I like that free power.

 

Thanks Michael for the education on how well they do and don't work in sun verses shade. That was great to read. I thought you always got enough power even filtered shade if long enough charge times occur, but, I can see that a full day isn't enough without full sun.

 

Glad you had time today to do this for me. Very nice of you to help me understand.

Edited April 18, 2016 by JAG1

[Mopar1973Man]

Now you understand why I chuckle about roof mounting solar panels on a RV. So using what I show on the house panels the RV would be unruly hot but you'd have power. The only reasons people place the panels on the roof is the lazy and hopefully no one can see the panels on the roof to steal them. That does pose a problem with free standing panels they can walk off. I would like a better spot to store my panels but don't have any where else to store them. Mine are fairly heavy and rather difficult to weasel out of the bedroom back outside.

 

Edited April 18, 2016 by Mopar1973Man

[KATOOM]

This thread got a little off track.....but still good info.

 

As for charging the trailer house batteries off the truck, I wouldnt suggest it.  A properly charged house battery will go undetected by the charging system but a weak house battery will place strain on the alternator.

 

I had an odd experience once pulling my trailer somewhere with weak house batteries.  Now I always make sure they're fully charged or I have them disconnected while towing.

[AH64ID]

I am going to replace my 10W roof mounted panel with a 100W roof mounted panel. Based on observations over the last few years camping with this camper I know that most of the time I get a decent charge window even in the trees. My issue is that I use more than 10W with the radio/fridge/etc on so the 10W wasn't ever charging and just slowing the rate down. 

 

I am only going with 100W because I already own, and take, a quiet Honda generator and while 100W is affordable going to 300 or 400W would cost more than I spend on gas over multiple camping seasons. Usually the sound of the creek/river is louder than the EU2000i anyhow. 

 

I really wanted to add a charge controller as well, as the 10W doesn't have one and on a sunny day parked in the yard the voltage can get a little high if there isn't much using 12V. I generally turn the solar off for this reason but a charge controller would allow me to charge more with solar between trips. 

 

I am not sure when I will get it installed but hopefully soon. Most the parts are here and I can reuse the existing wiring and just add the charge controller into the mix at the 12V distro panel. 

On 4/20/2016 at 1:30 PM, KATOOM said:

I had an odd experience once pulling my trailer somewhere with weak house batteries.  Now I always make sure they're fully charged or I have them disconnected while towing.

 

What kind of issues?

 

I have never even noticed, from the truck, anything different with low house batteries. I have a 300AH bank so when they are around 50% they need a long charge, which the truck cannot provide on a 2-3 hour trip. The truck provides max amperage for those 2-3 hours and I haven't ever seen anything odd. 

 

The wiring is just too small to allow for any decent current flow and the alternator will only output as much current as required to keep the truck voltage at the set point. 

Edited April 23, 2016 by AH64ID

[JAG1]

AH64ID, I've read that a charge controller is important  to turn off and disconnect the panel from the battery at night. Something about the stars and planets will pull every ounce of energy out of your batteries thru the panel.

[AH64ID]

Huh?? 

 

I guess the Ammeter will tell me that. 

[KATOOM]

AH64ID, what I had happen was while one time towing in some hot weather up the mountain I had the throttle act up almost like the dead pedal experience.....but not the same.  My only presumption after trying to figure out what happened was that because I was allowing the trucks charging system to remain connected to two house batteries which were in very very low charge condition, and because the Dodge wiring harness doesn't come equipped with any type of charge preference isolator, the alternator was probably working some serious overtime and generating a less than desirable sine wave of AC voltage out to all the neighboring electronics.  Thus freaking out my APPS.....  I'm sure it didnt help that it was around 95*, truck engine was toasty, and my RPM's in the 2400 range either.

 

I found this topic to be quite common on RV forums whereby people often discuss the ideas and experiences behind the need for an isolator or split charge relay between the tow vehicle and the trailer.  For various reasons too.....

 

So in point, I no longer tow with the house batteries in less than perfect charge condition, or if I have to then I'll disconnect them from the loop altogether.

[JAG1]

2 hours ago, AH64ID said:

Huh?? 

 

I guess the Ammeter will tell me that. 

you may have diodes that keep the charge inside the battery instead of loosing it to the night sky, but diodes do inhibit a good charge level desired, so as for me I would just bring the panels back inside

Edited April 23, 2016 by JAG1

[AH64ID]

I will not be disconnecting any panels. My 10w panel does not pull power from the batteries and the controller for my new setup says it has diodes. It's going to be a simple install.

[KATOOM]

I hope to getting some portable solar panels for my RV trailer soon.  But ya know how that goes.....  Soon can mean never get around to it.

[JAG1]

On ‎4‎/‎24‎/‎2016 at 5:01 PM, KATOOM said:

I hope to getting some portable solar panels for my RV trailer soon.  But ya know how that goes.....  Soon can mean never get around to it.

You and me thinks the same  so many projects which one today???

On ‎4‎/‎23‎/‎2016 at 1:32 PM, AH64ID said:

I will not be disconnecting any panels. My 10w panel does not pull power from the batteries and the controller for my new setup says it has diodes. It's going to be a simple install.

Take them diodes out of the equation and you would get more charging, then an automated on/ off switch would be best for night time.

Edited April 30, 2016 by JAG1