Solar panel upgrade questions

[Samm5892]

I recently had a local RV shop add a 200w panel in addition to the stock 80w panel on our 2021 Forest River Surveyor BHLE for a total of 280w. The solar controller was upgraded to a Go Power! GP-PWM-30-UL feeding two Battleborn 100ah batteries wired in parallel.

There are three sets of terminals on the controller, two sets of battery connectors and one set for the panels. The way the tech set it up, only the connectors for battery one and the panels have wires running to them. There are no wires going to the battery two connectors. Battery two does not show on the controller display (because it isn’t connected).


My questions are:

I assume the way it’s wired, the controller sees the two batteries wired in parallel as one 12v battery? If true, is this something I should be concerned about and am I getting the use of all the controller functions and batteries the way it’s wired?

I’m hoping there’s someone here has the answer before I tow the trailer back to the shop this upcoming week.

 

[* Boondocking *]

Yes, it is set up correctly for your one bank of parallel batteries.
The second battery connections are for a second battery bank that you presently did not have.

 

[Aussieguy]

when you parallel two or more batteries together they do in fact become on big battery
The Voltage stays the same 12v.... and the capacity (amp hours) increases

2 x 12v 100ah batteries becomes 1 x 12v 200ah

what is puzzling is joining two very different sized panels together
if it was not done correctly you can lose a lot of solar production

Your roof is small so it is important to get the most from your panels and the controller
Installer / sales guy would served you best by telling you to remove the small 80w and add matching 200w panels (or even bigger if possible)
I got 2 x 370w fits my roof real good


would have been even better they should have looked at maximum panels your roof could handle and installed a controller/wiring for that, then as budget or the need increased .......you could add the remaining panels later without having to buy another controller.

What you can do is keep the new panel and controller and add a second 200w
Ditch the 80w

if that does not meet your 12v charging needs swap out the controller fill the roof with max panels and add correct size MPPT controller

Keep the little PWM for a ground array.

 

[mysery1]

The 2 batteries wired in parallel are treated as one by the controller and should be connected to battery 1 terminals. What you wrote seems right. If you don't have the manual it's easy to find and download. Should tell you most of what you need to know.

 

[Samm5892]

Thanks everyone for the responses! I know next to nothing about this stuff but was happy to hear my assumption about two batteries being one was correct. I’m going to discuss ditching the 80w and adding a 200w panel.

 

[Boomerweps]

The solar controllers that have two sets of battery terminals are for Motorhomes that have two battery systems, one for the engine and one for the house. The engine uses a lead acid battery and then the house can use a LiFePO4. You should never parallel different battery types.

 

[Giboneys]

If the two panels are wired in parallel your 200 watt is only a 80 watt panel, I would get more information in how they wired the panels up. As others suggested I would ditch the 80 watt and add a second 200 watt but be careful of your expectations. 400 watts of solar with the Go Power PWM will have a hard time keeping up with your two LiFePO4 batteries and a small load.