Adding extra solar panels to 2003 AC Eagle

[kehodder]

I have a couple of 72 watt panels I'd like to add and connect to the factory panel on our coach. Can I just wire these two panels to the existing panel's wiring?

From reading other threads I'm assuming the original panel is connected to the BCC although, I remember when disconnecting the house batteries last year there was a seperate smaller wire (~12 gauge) that seemed to be the solar voltage. Could be previous owner mod when installing new Magnum inverter maybe? Anywho what/how should I check before adding these extra panels please?

[DavidEM]

Factory installed solar panels are usually wired to the solar controller and then directly to the battery through an inline fuse located near the batteries. At least that is how my newish Thor Axis was wired.

You can install two additional 72 watt panels in parallel with the existing 100 watt? panel. But that will create a voltage drop in the typical 10 gauge wire from the panels to the controller with the current from the two panels added.

It might be tolerable if the panels are within 10-15 feet of the controller.

David

[kcmusa]

You need to check the voltage of the panels. They must be very close to one another.

[fatsurf]

You will need to fully understand the present system to accurately answer that question. Most important answer will be the specs on the existing solar controller followed by the existing wiring.

[kehodder]

Appreciate the responses as I don't want to pooch my electrical. I mistakenly posted to the fleetwood rather than the American Coach sub-thread. Gary RVRoamer will hopfully chime in as he has good knowledge of these era American Coaches. My rough understanding is that Amer.Coach factory panel is wired to the BCC but unsure if the BCC has a solar controller built within it (I assume it must though).

The extra panels I'd like to add are Solavolt model SV7500 with ratings of PMax 72.2W, Voc 21.8V, Isc 4.55A,Vpmax 17.3V, and Ipmax 4.17. I'll check the original panel and see there is a label once I melt the dicor off and lift it up. Failing a label on the original panel (again assuming it's the original) I guess I'll just check the output voltage with multimeter.

I'd like to beef up the solar capability as the coach has a Samsung Fridge now and it'll draw down the 4 house batteries to where the auto-gen comes in about 12 hours.

[kehodder]

I was mistaken, I checked the two extra wires connected to the battery and they do NOT go to the factory solar panel. Smaller orange is associated with the battery disconnect and the larger red one is associated with the charger/inverter.


I then opened the BCC, using the schematic from Intellitec's site I checked the voltage to the solar wire connection. 17.7V coming from panel on this partially overcast day.

Then covered the solar panel with a blanket and got ~4.5V.

Now I just need someone with solar system knowhow as to what I do for adding my two extra panels.

[DavidEM]

Your latest post indicates that there is no solar charge controller between the panels and the BCC. That is very bad and will result in overcharging your batteries.

You need a solar charge controller with its input connected to the panels and it’s output should be connected to the batteries.

David

David

[kehodder]

Could be that the BCC in our coach is also functioning as the solar controller. The BCC manual states:

"The Solar Charger is used to control the output of roof-top mounted solar panels to the coach battery. When the
ignition is off, the battery is below 12.8 volts and there is more than 14.0 volts output from the panels, the
controller will close the board-mounted charging relay, tying the solar panel to the coach battery for 30 minutes.
The controller will turn the charging relay off for a 2-minute resting period and then check the coach battery
voltage. If the voltage is less than 12.8 volts, the cycle will repeat."

I have no issue with adding solar controller if necessary, might not need one if the BCC is handling the task. Since my panels are similar I figured I'd just wire the three panels in parallel....just not sure if my BCC can handle the extra capacity.

[kehodder]

I re-read the above quote from the BCC manual....I guess the factory panel is only for keeping the coach battery (chassis) rather than the house batteries. If this is the case I'd probably be best to add the two panels independent of the original. Would mean running seperate wiring from these Xtra panels to the house batteries with a charge controller between. More work but at least I'd boost my off grid capability.

[fatsurf]

With the work it takes to install solar panels you might want to rethink the 73 watt panels and go with a couple of 200 watt panels and an mppt solar charge controller. That will add a significant amount of power to recharge your batteries. With your residential fridge you can't have too much solar as I've learned since installing my panels last month.
//Greg

[Grizzly73]

I agree, I'd add as much solar as you can, especially since you have a residential refrigerator.

I'm an electrical engineer and sell a few brands of solar controllers, PM me if I can help you out or quote you anything.

Shawn

[kehodder]

I have access to a 20A Rich Solar mppt controller. They any good?