Total newbie and confused

[HOOOPTEEE]

Hi everyone, I have a 2006 Winnebago class C with an upgraded Progressive Dynamics PD4645V charger and stock inverter. Now, I'd like to add a few solar panels. The plan was to drop the solar wire down the fridge vent --> to the solar charger (to be mounted under the stove) --> pop a hole through the floor and run welding wire (in conduit) under the rig to the coach battery located under the entry stairs.

I just saw a youtube video about a guy who wired the solar controller/charger directly to the existing battery charger under the fridge and now I'm all confused. What do you guys think? If I can go to the PD4645V, do I pigtail?

OR should I stay with the original plan and go from the solar controller/charger to the battery and bypass the house charger altogether?

 

[creativepart]

Let's get a few things straight. It would help to know if you have a "Progressive Dynamics PD4645V charger and stock inverter" as you said, or if you have a Converter/Charger. Perhaps you misspoke about the "inverter."

How much solar do you plan to install? I ask because the current coming out of your solar charge controller generally is not all that large. So, using heavy gauge "welding wire in conduit" is overkill unless you're installing 800w or more of panels. Typically, on a Class C you'd see something like 400w and that produces less than 30-amps max coming out of your charge controller.

What charge controller are you planning to use, and are you wiring in Parallel, Series or a combination of both?

I haven't seen the YouTube you mention, but I'd have to guess that that guy just used the battery connection at the charger simply for wiring convenience - not actually using the charger for anything. It's very unusual and your plan to wire directly to the battery bank is the right way to go - just reconsider the very heavy wiring from controller to the batteries. For 30-amp you'll be fine with 10ga wire unless it's a long run and then consider 8ga.

 

[uchu]

I agree. Charge controller from the panels must be connected directly to the battery.

 

[Gary RV_Wizard]

Charge controller from the panels must be connected directly to the battery.

Why? The converter/charger and the solar regulator both go to the battery terminals, so they are conjoined regardless. The caveat is that connecting at the converter needs to be done on the output side, i.e. the charger feed to the batteries.

 

[PJ Stough]

I believe that this RV has a small, perhaps 300 watt inverter, separate from the converter/charger, to run the TV and a couple of outlets.
I dont see a problem connecting the output from the solar controller to the output of the converter/charger if the wires running from the converter/charger to the batteries are big enough to handle the additional load of the output from the solar controller. That is how I have my system wired.

 

[creativepart]

I agree that it should work, but it seems wrongheaded to have it wired this way. You wouldn't wire the Converter/charger to the solar charge controller to feed the batteries - even though you could. So, why would you wire the solar charge controller to the converter/charger? Just because you can?????

The point is... this wiring scheme is just to avoid separate wiring to your battery bank. It's not using the charge portion of the converter/charger just the output wiring to the battery bank.

 

[PJ Stough]

I agree that it should work, but it seems wrongheaded to have it wired this way. You wouldn't wire the Converter/charger to the solar charge controller to feed the batteries - even though you could. So, why would you wire the solar charge controller to the converter/charger? Just because you can?????

Electrically, I dont think it makes any difference. If it meant using shorter wires, I would wire my converter/charger output to the output of the solar controller.

 

[creativepart]

I'd like to see the video - can you provide a link to it?

 

[creativepart]

Electrically, I dont think it makes any difference. If it meant using shorter wires, I would wire my converter/charger output to the output of the solar controller.

Perhaps, it would be electrically more "Kosher" to run both the converter/charger and the solar charge controller to a couple of positive and negative buss bars and run the buss bars to the battery bank.

My Winnebago wires the solar charge controller directly to the battery bank and did so from the Factory. I don't have a converter/charger I have an inverter/charger - but it is located in the same compartment as the solar charge controller and the factory didn't utilize that charger-to-battery connection to connect the solar charger.

 

[HOOOPTEEE]

Let's get a few things straight. It would help to know if you have a "Progressive Dynamics PD4645V charger and stock inverter" as you said, or if you have a Converter/Charger. Perhaps you misspoke about the "inverter."

How much solar do you plan to install? I ask because the current coming out of your solar charge controller generally is not all that large. So, using heavy gauge "welding wire in conduit" is overkill unless you're installing 800w or more of panels. Typically, on a Class C you'd see something like 400w and that produces less than 30-amps max coming out of your charge controller.

What charge controller are you planning to use, and are you wiring in Parallel, Series or a combination of both?

I haven't seen the YouTube you mention, but I'd have to guess that that guy just used the battery connection at the charger simply for wiring convenience - not actually using the charger for anything. It's very unusual and your plan to wire directly to the battery bank is the right way to go - just reconsider the very heavy wiring from controller to the batteries. For 30-amp you'll be fine with 10ga wire unless it's a long run and then consider 8ga.

Good point. I'm installing 400w (4x100w in a combination of series and parallel) for now but am trying to build for the future in case I need more. The upgraded Progressive Dynamics PD4645V charger and stock inverter are two separate "things." the inverter is whatever Winnebago installed at the factory. I have an Epever 40A MPPT controller. My original plan was to go from the controller to the battery but that video got me thinking if there was an easier way. I have a tendency to overthink things. I'm going about 10-15ft from the controller to the battery, so I figured that I'd rather oversize the wire and limit voltage loss.

 

[HOOOPTEEE]

I'd like to see the video - can you provide a link to it?

Minute 19:00'ish

 

[PJ Stough]

Good point. I'm installing 400w (4x100w in a combination of series and parallel) for now but am trying to build for the future in case I need more. The upgraded Progressive Dynamics PD4645V charger and stock inverter are two separate "things." the inverter is whatever Winnebago installed at the factory. I have an Epever 40A MPPT controller. My original plan was to go from the controller to the battery but that video got me thinking if there was an easier way. I have a tendency to overthink things. I'm going about 10-15ft from the controller to the battery, so I figured that I'd rather oversize the wire and limit voltage loss.

I would say that there is nothing wrong with your plan, with the caveat that the wires running from the converter/charger to the batteries are heavy enough to handle the additional load of the output of the charge controller.

 

[HOOOPTEEE]

I believe that this RV has a small, perhaps 300 watt inverter, separate from the converter/charger, to run the TV and a couple of outlets.
I dont see a problem connecting the output from the solar controller to the output of the converter/charger if the wires running from the converter/charger to the batteries are big enough to handle the additional load of the output from the solar controller. That is how I have my system wired.

Why? The converter/charger and the solar regulator both go to the battery terminals, so they are conjoined regardless. The caveat is that connecting at the converter needs to be done on the output side, i.e. the charger feed to the batteries.

The thinking is one less hole to drill through the floor for the solar controller to the battery wire. Going from the solar controller to the charger just seems easier but it sounds like the preferred router is going from the solar controller directly to the batteries.

 

[PJ Stough]

Minute 19:00'ish

I see a few things that dont make sense in this video, but how the output from the solar controller to the batteries is connected is not one of them.

 

[creativepart]

I watched the video. I guess it makes sense in a Travel Trailer because of the long run from the middle of the RV to the front of the A-Frame where the battery resides. I'd assume that with a class C your fridge is close to the middle of the RV and so is the battery bank under the stairs.

It would also be assumed that the battery cables from a 45-amp charger would be of proper size for a 40-amp solar charge controller.

I still would rather see buss bars utilized rather than splicing wires together. AND, I'd never use twist on wire connectors in an RV 12v wiring project.

 

[PJ Stough]

I watched the video. I guess it makes sense in a Travel Trailer because of the long run from the middle of the RV to the front of the A-Frame where the battery resides. I'd assume that with a class C your fridge is close to the middle of the RV and so is the battery bank under the stairs.

It would also be assumed that the battery cables from a 45-amp charger would be of proper size for a 40-amp solar charge controller.

I still would rather see buss bars utilized rather than splicing wires together. AND, I'd never use twist on wire connectors in an RV 12v wiring project.

I agree, I would not use the twist on wire connectors.

 

[creativepart]

I can see the logic. It makes some sense. It's just not a shortcut I'd take unless the wire run was too far to the battery bank.

 

[Gary RV_Wizard]

The net of it is that both chargers are feeding volts/amps to the same batteries and if shore power is present the batteries see the combined feed. With a few caveats about wire size, length, and quality of the connections, it makes no difference at all where the two sources are joined. Electrically, the batteries see the exact same thing.

 

[HOOOPTEEE]

I watched the video. I guess it makes sense in a Travel Trailer because of the long run from the middle of the RV to the front of the A-Frame where the battery resides. I'd assume that with a class C your fridge is close to the middle of the RV and so is the battery bank under the stairs.

It would also be assumed that the battery cables from a 45-amp charger would be of proper size for a 40-amp solar charge controller.

I still would rather see buss bars utilized rather than splicing wires together. AND, I'd never use twist on wire connectors in an RV 12v wiring project.

So wire from solar controller to a bus bar that is also connected to the Progressive Dynamics charger?

Why? The converter/charger and the solar regulator both go to the battery terminals, so they are conjoined regardless. The caveat is that connecting at the converter needs to be done on the output side, i.e. the charger feed to the batteries.

Assuming that the wire running to the batteries can handle the extra amperage, right?

 

[creativepart]

So wire from solar controller to a bus bar that is also connected to the Progressive Dynamics charger?

I would install buss bars. Then crimp on ring connectors on the 3-pairs of wire; one pair from solar, one pair from converter/charger output and a third pair from the battery bank. Then give each wire their own post on each buss bar.

Assuming that the wire running to the batteries can handle the extra amperage, right?

In essence you will not be adding any extra amperage. When plugged into shore power your converter/charger will take on charging your batteries. When not connected to shore power your solar charge controller will take on charging your batteries. The solar charge controller reads your battery voltage and applies charging based on that voltage. When your converter/charger is charging your batteries at 13.7v (or more) your solar charge controller is smart enough to read that voltage as battery voltage and stop nearly all charging.

People mistakenly think if they are plugged into shore power and charging a battery with 30 amps from a converter/charger and also are parked in the sun that their solar charge controller is adding another 30 amps for a total of 60 amps. But in my experience, my 300w of solar only applies it's charging amps when no other charger is present. This includes while driving and getting a charge from the alternator.