Solar newbie questions...

[bertschb]

I ordered the new solar package for our Solitude 310GK-R and I'm planning on upgrading it a bit. I'm doing a lot of research but I still have a couple questions.

First, with the availability of 300w panels, why do people still use 100w panels? I don't think the 300w panels are even twice as large so you can get more watts for less roof space, less wiring, fewer brackets and holes in the roof, etc.

Second, just curious - do most of you wire panels together in series or parallel?

My plan right now is to add a second 300w panel to the factory 300w panel for a total of 600w. I know that isn't much but I'm hoping I can do that without changing the wiring, charge controller or inverter. Still need to research that further. I'll then replace the two lead/acid batteries from the dealer with two Battleborn batteries. I don't plan to boondock with this setup but I hope I'll be able to run my residential fridge while driving and maybe have enough battery to stay overnight somewhere with no shore power (basically just fridge and lights - maybe a little furnace).

[cookinwitdiesel]

If you connect your panels in series, then the voltage stacks and not the current, this will allow you to use the standard 10 awg wiring and MC4 connectors. You will need to keep the voltage of the entire string under the rating of your MPPT controller. Also keep in mind what the output current is for you MPPT is. That current and your battery voltage will dictate how much wattage you can have on your roof for that MPPT.

[jmbopp]

Connecting in series is the preferred method but it requires a MPPT controller and the panels should be matched to each other. And if you need to replace the controller make sure the new one can be programmed for the Battleborns.

[el Rojo]

Connecting in series is the preferred method but it requires a MPPT controller and the panels should be matched to each other. And if you need to replace the controller make sure the new one can be programmed for the Battleborns.

Not necessarily the prefered method. We choose to connect in parallel so we could add additional panels without having to change the whole system. We started with 4 180 watt panels and then added 2 200 watt panels. Since we were wired in parallel this was a simple add. I do believe we lost a little efficiency being in parallel but adding to the system is easier.

YMMV

Red

[gbkims]

Since the 300W Jaboni solar panel's Open Circuit Voltage is 39.85 Voc, I think you'd need to connect another panel in parallel so not to exceed the MPPT max input voltage of 45VDC.
Or change to another MPPT that has higher input voltage specs.

Jaboni 30A MPPT charger specs:
Max Solar Open Circuit Voltage 45VDC
Max Input Current 30 Amp DC
Max Wire Size 10 AWG

300W Jaboni solar panel specs:
Open Circuit Voltage 39.85 Voc
Maximum Power Voltage 32.26 Vmp
Maximum Power Current 9.30 Imp
Short Circuit Current 9.75 Isc

[BB&LAB]

The above responses all have merit. To your question regarding 300 watt panels, they are considerably larger and nothing wrong with them as long as the real estate is available. I have 3-320 watt panels which leaves little room left. These panels are considered residential and higher voltage and are cheaper per watt than the typical 12V panels. One thing you may consider if you decide to add more panels, if your charge controller cannot handle the additional wattage and voltage is to add a second charge controller specifically for the additional panels.

[bertschb]

Thanks for the feedback guys. I really appreciate it. Since a single 300w panel takes up less space than three 100w panels, I'm just going to use 300w panels. Seems much simpler.

[cookinwitdiesel]

The 300w panels should be better overall assuming you have the space for them. On my 3740bh, I can get a lot more wattage up there by using smaller panels since I can fit more of them (13x 200w panels - 26" wide vs 5x 300w panels - 39" wide). The issue is that the 39" panels are a hair too wide to go left and right of the AC without sticking out so placement for them is difficult.

[bertschb]

The 300w panels should be better overall assuming you have the space for them.

Yeah, I'm going to wait until my new rig arrives and then measure the roof to see how many panels I can add. Looking down the road, the most I could see using is four 300w panels. I also need to see exactly what equipment gets installed on my unit. I know what the GD website shows but I'll wait to see what actually gets installed.

[cookinwitdiesel]

Well, they are going to put one panel on the roof in the middle in a weird position. You should be able to easily get 2 more I would think (before and after AC units on roof). Depending on how things are spaced, you MAY be able to get 4 panels total up there.

Pretty much you can do 2 side by side where there is NOT an AC unit. If there are other obstacles, you can do one turned sideways or one on one side of the trailer. The space goes fast when you are looking for large unobstructed squares on your roof!