Want to install solar, questions

First off, my wife is not using her humidifier with her CPAP.

I know 11.8V is not good for the batteries that is what I'm trying to stop happening.

Presently I have no idea the size of the wires from the roof. They are behind a panel in my lower kitchen cabinet.

My Batteries we'll be about 2 to 3 feet from my batteries so that we'll be a short run.

The Zamp controller that I have does have the capability to use a battery t4mperature with sensor with it. It also has capabilties of an remote meter. It also has the capabilities of setting it for different batteries and has 5 levels of charge capacity.

I'm still can't figure out why my 2 GRP27 batteries should drop down to 11.8V just over night. We have a Lithum battery for my wife;s CPAP and it well run her CPAP for 2.5 nights from a full charge. It is a small battery. I really think I have something that is pulling a lot of power that it shouldn't. Also my coach has an absortation fridge and is ran on propane when we are stopped.

I want to be able to dry dock more do I need to be able to run for more than one night. I could set met generator to start up when my batteries drop to a certain level as it has a smart controller that a person can program for all kinds of different things. But who wants a generator to start up in the middle of the night even though it is a quiet diesel and is very quite and can hardly be heard inside the unit.

I know I'll eventually get this figured out but in the mean time I'll still be using the GRP 27 and running them down I guess till I get home and get the bigger battery bank. I really don't care about them as they are just going to be core charge when I buy new batteries.

Thanks for every bodies comments I apprecitate them all/

Replace the Zamp controller with one that has adjustable voltage set points and a battery temperature sensor.

Ebay the Zamp.

Do you know the thickness of the solar wire pre install?

KD4UPL wrote:
30 amps would be the total of all the Imp ratings of the solar panels wired in series. This would be around 500 watts total.
Assuming the panel's Vmp is 18v then it would be 18V x 30A = 540 watts.

Couldn't run 5 panels in series with a PWM controller.

I've had 5 100 watt panels flat mounted on my roof through this summer, and most of the time they peak out at around 25 amps. My Bogart SC 2030 will only pass 30 amps, but will handle quite a bit more than that and just clip the excess. As a result I've just recently added a 6th panel. If you tilt the panels, climb up on the roof occasionally and clean them off etc they put out a fair bit more output so results can vary significantly.

30 amps would be the total of all the Imp ratings of the solar panels wired in series. This would be around 500 watts total.
Assuming the panel's Vmp is 18v then it would be 18V x 30A = 540 watts.

Your two GR27 batteries give you about 160 Amp Hours. Four GR31 batteries will give you over twice that amount about 400 Amp Hours.
The 30 amp controller can handle five 100 watt (12 volt) panels connected in parallel.
Hard to say if the pre-wire is of the proper gauge to handle 30 amps without any voltage drop.

My question is how many 100watt paneles well this controller support? It is a PWM not a MPPT controller.

Typically, around 4 or 5 X 100W panels. Depends on output of the panels and your situation. Your Zamp controller should have the specifications of upper limit listed.

For now, if your DW can get by without the humidifier part of the CPAP, then it would draw less from the battery bank overnight.

A 100w panel will supply approx. 6.2 amps aimed at a full sum. How much you get with it flat on the roof depends on where you are and what time of year. A PWM controller needs some "margin" not to go over its 30a rating so you could run four 100w panels in parallel as a rule.

However you are not stuck with that controller. You don't have to get 100w panels unless there is a specific roof real estate issue. Do get a bigger battery bank now, and do lots more research on solar before buying anything so you have a better idea of your options.

You might be limited somewhat by the gauge of wire they used and how far the controller has to be from the battery bank, but even that can be worked around as needed if they didn't do it the best way.

Pulling the batteries down to 11.8 is not good for them.