Want to install solar, questions

[Butch50]

We recently got our new 2017 Nexus Ghost and I had it pre wired for solar. Nexus provided (in a box) a Zamp 30 amp Digital Controller with the pre wire.

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

I'm a newb when it comes to solar and looking for help.

My coach currently has 2 grip 27 batteries but I want to go to 4 Grp 31 AGM batteries. Right now our 2 Grp 27 batteries won't even last a night. I turn the furnaces down to 60 degrees for the night . We have all LED lighting and when we are dry docking we do not run the inverter nor run TVs. We use our IPads and IPhones but do not try to charge them till we start driving the next day. While driving I see 14.2v from the truck alt. After being parked I we'll see the voltage level off at 12.5 to 12.6V but after the night I see 11.8v in the morining. My wife does run a CPAP at night that operates off 12VDC.

We are on the road right now so I can't really start looking for parasite voltages draws.

When I return home I can do more trouble shooting.

Thanks for any help.

I don't have access everyday to the Internet as we use our IPhones for hot spot but have to watch our data usage.

[KD4UPL]

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.

[Boon_Docker]

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.

[westend]

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.

[BFL13]

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.

[CT_WANDERER]

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