Large Solar Panels on a FWC

[Bwht4x4]

What's that largest solar panels folks have put on their FWC? Regardless of the weight factor and difficulty in pushing the top open.

I'm considering adding a solar panel and have been looking at the 160 and 190 watt panels. I want a panel large enough to generate enough power on a cloudy day to power my appliances and charge the batteries.

 

[MarkBC]

I have two 120-watt PV panels on the roof of my FWC Hawk.
Together they weigh around 45 - 50 lbs, which is why I added the "roof lifting helper shocks thingys".

 

[Bwht4x4]

Wow, thanks Mark! I can't imagine you ever running into problems with charging your batteries.

I need to crunch some numbers but I'm thinking a 160 watt panel should do what I will need it to do.

 

[MarkBC]

Wow, thanks Mark! I can't imagine you ever running into problems with charging your batteries.

I need to crunch some numbers but I'm thinking a 160 watt panel should do what I will need it to do.

Actually, I did run into a problem charging my batteries: I burned out my undersized solar charge controller!
I got away with that frugality (cheapness) for about a year...and then I didn't.

160 watts is more than most people with our size of campers use. Unless you spend a lot of time under trees or heavy clouds or at high latitudes and camped for several days without driving-charging, you should be fine with that solar capacity.

 

[ntsqd]

The moment that I pulled the covering off of our 100W single panel after making the final connections I was seeing 3.6A on the Tri-Metric meter. It is mounted with a slight drainage slope but essentially flat on the roof, though that was the middle of a sunny day on the Lower Left Coast. My plan, which was round-filed by a sale on the panel, was to watch what our usage actually was with the meter over a couple of trips, and then scale the panel appropriately.

No idea what the panel weighs, but I can feel the difference in lifting the roof and I've been reading the roof lifter thingies thread weighing our options.

 

[Bwht4x4]

Mark,

A lot of my camper usage will be on hunting trips and these can last anywhere from 5 to 20 days. Last year I camped for 21 days on a CA elk hunt under quite a thick canopy of pine trees. With a solar panel I wouldn't be able to camp in a spot like that one and get much of a charge even with a big panel. Also on the trip I had 2-4 day periods of rain and clouds. I think the 160 watt panel will be perfect for these types of trips.

ntsqd,

Once I install a panel I too am thinking of adding the roof lifter shocky things. Right now a refrig and panel is priority #1. I've got a week long bachelor party coming up in late May that I want to be ready for.

 

[Bwht4x4]

Mark,

Which solar controller are you running with your two panels?

Thanks

 

[MarkBC]

My new solar charge controller -- after I fried the old one -- is a Blue Sky Energy SB2512iX-HV.
It's an MPPT-type charge controller. If you don't care about MPPT (I do, because I have my panels wired in series) you can spend less on a PWM-type charge controller.

 

[Bwht4x4]

I'm going to go with the MPPT technology since a lot of my use will be from Sept to Dec and with cloudy days. I want to maximize everything with this system.

Thanks

 

[ntsqd]

I'm going to go with the MPPT technology since a lot of my use will be from Sept to Dec and with cloudy days. I want to maximize everything with this system.

Thanks

Given your use I think that's a good call. I didn't see the price difference paying off in our use.

I just wish that I could feed the alternator charging current to our charge controller to get the 4 stage charging from it too. Instructions with our controller specifically say not to.

 

[Lighthawk]

We just returned from our maiden voyage with 110 watts up top. It was great for our needs (laptop, 2 phones, tablet, camera batts, etc.). We were out for four days in DV and were stationary for three nights/two days. Panel kept up great!

As an experiment I put the 3-way fridge on DC for the eight hour drive home. Normally I would never do this, since the fridge draws a lot of current. The refer cooled while we drove home. I switched it off when we were unpacking, but forgot to check the battery volts until this morning. It was at 12.48v

 

[Bwht4x4]

Does a 3 way refrig draw DC current from the truck when your driving?

 

[Kispiox]

The DC fridge draws from the camper house batteries. The truck when running recharges the camper house batteries on demand with priority to the truck battery(s) first.

 

[billharr]

I was never able to keep things cold running DC on the old 3 way. You are running resistance heaters and 12v is not a lot of power. Hope the DC compressor works as well as everyone says it does.

 

[Kispiox]

Just returned from almost four months fishing the Olympic Peninsula.

My two cents worth. You can over size a solar panel for a given task. AGM batteries like to be duty cycled. They do not like to be fully charged/charging all the time, nor do they like to be fully discharged. These activities will shorten their life, number of duty cycles. On my Hawk with a 95W panel even in canopy and rainy conditions I sometimes kick in the DC Refer to cycle the bank down. I don't see a need for more solar capacity? Run the Refer on propane. That is the primary draw if on DC, but doesn't need to be. I no the lawyers say not to have propane on while driving but the refer runs fine. You can buy a whole bunch of propane for the cost of upsizing your controller and another panel . You will also cause yourself more personal power management to properly manage and duty cycle your house bank. Or you can buy new batteries more often.

But then, you could alway invert to a 110VAC blender for cocktails to off-set the concern. Come to think, that may make it worth while...

 

[Kispiox]

Billharr,... Ditto your comment on the DC fridge. I find it does not cool adequately even in cool conditions. If run for a prolonged time stuff in the freezer is only partially frozen. Propane is the ticket when running and gunning.

 

[MarkBC]

Ditto your comment on the DC fridge. I find it does not cool adequately even in cool conditions.

Are you talking about a 3-way fridge run in DC mode?

 

[Kispiox]

Yes, 3way. The only time I run my refer on DC is for a short period of time when I cannot find a level plate to park. (On propane the refer likes to be somewhat level, although new refers are much better about this than older models) I don't do this very often because I almost always find a level enough place to park for the propane to function.

 

[ntsqd]

I've run the refer on either propane or DC while traveling. So long as we got it down cold enough on 120VAC before leaving it usually can hold it's own on DC. Asking it to cool things down that aren't already cold or trying to cool it down from ambient is likely not going to happen on DC and may not happen on propane.

Have been looking at compressor refers, they're just not in the current budget.

 

[billharr]

Yes, 3way. The only time I run my refer on DC is for a short period of time when I cannot find a level plate to park. (On propane the refer likes to be somewhat level, although new refers are much better about this than older models) I don't do this very often because I almost always find a level enough place to park for the propane to function.

You do realize that a 3 way fridge (absorption cooling) needs to be level to work no mater if on propane, 12v or 110 volt. All are just heating the gas in the system.