Replacing an inefficient Zamp solar kit with a Overland kit

[Vic Harder]

We have the same FWC Fleet with the same solar system, batteries and refrigerator set up and are happy with its performance. It does what we expected it to do.

Expectations are everything. I have 250AH of battery, and 265W of solar on the roof (plus 200w portable). At the moment, I would be glad to get 50W out of the roof panels for 4 hours, given the angle of the sun (I'm in Calgary) and the slight dusting of snow on the roof today, even in super bright sunshine. That's 16AH or so. I would not expect my rooftop solar to keep up with demand from my furnace/lights, even at a low 5A max total draw at most times. 5 hours at 5A = 25AH, which is what I also see on my Victron BMV.

The OP's batteries and solar array are way smaller, and have rain/cloud to contend with. My system would not cope well in those conditions for more than 4 days, tops. And installed myself, it was still $3000 USD in parts.

 

[roverjohn]

The OP sounds like a perfect candidate for a propane fridge. Contrary to a lot of peoples opinions they are amazingly cost effective.
It will reduce your electrical usage considerably and will work even if your batteries are stolen. I like compressor fridges as much as the next guy but in this guys case a propane fridge would solve his problems.

If you are staying with electric you can increase the voltage of your array by using a good MPPT controller. They usually allow for a much higher input voltage than a cheap PWM controller. You'll get far more amps into your battery on low light days. Also, go with two 6vdc AGM batteries in series as a single series connected string is always better than paralleled 12vdc batteries

I'm an extreme DIYer so the prices I've seen in this thread seem insane to me but I guess that's just me. On a lark I purchased a little Champion 800 watt genset the other day and I'm pretty impressed by it. I think they are available for around $250 maybe less and may solve your issues while you decide what to do. You'll also need some sort of charger unless the $28k you spent included some sort of charger. Even if it did I probably wouldn't trust it as most camper chargers are pretty poor.

It does sound to me like FWC is only looking at your wallet and not the bad press you are understandably laying on them here.

 

[patrkbukly]

I love my FWC but the electrical system/design is BAD.

Step 1: Ditch the crappy stock fridge for an ARB or Dometic 12v - that should solve the majority of your power issues. I don’t know why FWC insists on installing the inefficient 2/3 way fridges but they are truly terrible. The only advantage is the front opening.

Step 2: If that doesn’t solve it completely, just take the stock panel off and buy 2x Renogy 100W panels for $260 and install them. You can buy a cable off of Amazon that will connect both panels to the camper plug on top.

Just did that and man what a difference. The Dometic top loads are so efficient. .75 amps is nice.

 

[So Cal Adventurer]

I did my own solar based on Vic and others advice here.

I am running the Victron system with both the battery monitor and the MPPT monitor.

I am running (2) 175 watt NewPowa panels on the roof for a total of 350 watts.

I BRIEFLY had a portable with my old setup, and it was a pain in the ass, big, bulky, and took up a lot of valuable storage.

No reason at all, NOT to put a second panel on the roof, Renogy make the Y adapter and it literally takes 2 second to wire it up if you already have one up there.

Doing it myself was a fraction of the factory price, and it works flawless, even in crappy conditions.

My .02

 

[Vic Harder]

350 watts! Nice! Do you camp much in the shade/treed/rainy areas? I sold my portable setup and am not missing it, yet. New build on the Puma will have 300+ watts on the roof, and the truck alternator setup is ready to go as well, so am really thinking portable will not be necessary.

 

[So Cal Adventurer]

Vic

Yeah, the NewPowa 175 watt panels are the same dimensions as the Renogy 100 watts and fit PERFECTLY between the frame rails and even fit nicely behind the second vent.

Highest rated on amazon and very affordable. Highly recommended.

I camp in any conditions, shade, rain, etc... But I almost never stay in one place more than one night, I am generally always on the move.

The 350 is mainly for when I'm at the house so everything stays tip top, or if camped for extended periods with big draw.

SIDENOTE: I have not shut my ARB fridge in the truck off ever in almost three YEARS!

 

[CougarCouple]

I'm kinda new to this solar, so I have a question. Looked at the NewPowa 175 and it listed the panel as a polycrstalline , I thought the Monocrystalline Solar Panel is the better technology for collecting the energy?

Thanks Russ

 

[ckent323]

Why not go with semi flexible panels on campers? They are much lighter and I have seen them up to 160 Watts.

I put two 100 Watt Grape solar panels on our camper roof and my back is surely disappointed I did not use light weight semi flexible panels. Two 160 Watt panels would be plenty.

I have thought about doing a retrofit. I would mount the semi flexible panels on a thin sheet of Aluminum then attach that to my existing mounts which hold the panels about 1" above the camper roof to provide airflow for heat dissipation.


Clarification: My camper only has lift struts (internal) in the front. The back is heavy because there are no struts. I could Install struts but I think I would rather upgrade the panels to semi-rigid and higher wattage rather than add rear struts. As has been pointed out, semi-rigid panels are more expensive.

Craig

 

[So Cal Adventurer]

I'm kinda new to this solar, so I have a question. Looked at the NewPowa 175 and it listed the panel as a polycrstalline , I thought the Monocrystalline Solar Panel is the better technology for collecting the energy?

Thanks Russ

Yes, the ones I am using are mono..

Newpowa 175W 175 Watt 12V... https://www.amazon.com/dp/B0772PD96K?ref=ppx_pop_mob_ap_share

CORRECTION, after just checking my amazon orders, I am using one of their 175 watt panels in the front and their 100 watt panel in the rear (to fit with second vent)

So I’m running 275 of solar, NOT 350

 

[So Cal Adventurer]

Why not go with semi flexible panels on campers? They are much lighter and I have seen them up to 160 Watts.

I put two 100 Watt Grape solar panels on our camper roof and my back is surely disappointed I did not use light weight semi flexible panels. Two 160 Watt panels would be plenty.

I have thought about doing a retrofit. I would mount the semi flexible panels on a thin sheet of Aluminum then attach that to my existing mounts which hold the panels about 1" above the camper roof to provide airflow for heat dissipation.

Craig

Personally, I don’t see the benefit..

I upgraded my lift struts and the roof takes the same amount of pressure to lift now than it did without solar. That’s a non issue.

For me, I’d prefer tried and true reliable versus something new to the market that hasn’t really seen 4-5 years of extreme weather to prove its durable enough.

That’s my .02

 

[Vic Harder]

Kent, flexible panels tend to be much more expensive (at least up here in Canada).

275w is still very nice. i have 265 and am looking at 42w of power going into my batteries right now. my 130l truckfridge also has not been off since installed 30 months ago

 

[pvstoy]

I do have 3 (three) Overland Solar 160 watt panels on my roof for 480 watts. Yes they are more expensive, but... I like them.

I have noticed in rain that the battery is still being charged. I run them in parallel as the voltage I normal see is 28 volts. That is enough head room when it is cloudy and raining when less voltage is being produced to still produce some charging. Above 19 volts the MPPT charger can make something out of. But if your panel caps out at 20 volts when it is cloudy or raining it is not giving your controller much to make anything in return as it might be putting out 12-15 volts.

If I had multiple panels that were around 18-22 volts I would have wired them up in Serial to increase the voltage and sacrifice amps, this would do much better in low light conditions.

I have found these panels have been working out really good and have yet to use the trucks alternator to do any help charging. I do have the very inefficient Dometic 130 liter DC refrigerator. But I really like the large freezer space.

 

[GeezerMike]

Here is a piece of information about a Zamp solar setup that is implied, but it is not stated directly.

A Zamp PWM Charge controller combined with a 160 watt Overland solar panel only puts out 80 watts on a perfect day. Replace that (or any) PWM charge controller with an MPPT charge controller and it will allow the solar panel to produce 160 watts.

A solar panel on a perfect day pointed directly at the sun at that time is a variable power generator from 0watts to Max watts dependent on the voltage it is connected to. As an example, for maximum power, the Overland 160watt panel needs to be held at 27.3 volts to produce its maximum power (Vmp in specs). A Zamp (or any) PWM charge controller holds the panel at battery voltage, roughly between 12 and 13 volts, or roughly half the voltage needed by the Overland 160 to produce 160 watts.

The way to calculate the wild-asp maximum output of a solar panel using a PWM charge controlker is to multiply the maximum current output of the solar panel (Isc) which for the Overland 160 watt is 6.27 amps (generous) and multiply that by the battery voltage (I’ll use a generous 13volts), which results in 81.47 watts output max(no way it will get that high).

An MPPT charge controller can get more power out of a solar panel by using an expensive internal DC-to-DC converter to increase the voltage seen by the solar panel to hold the solar panel at maximum power voltage (Vmp) which results in maximum power amps (Imp). For the Overland 160 watt panel, Vmp=27.3 volts, and Imp=5.86 amps, to get watts 27.3x5.86=163 watts.

When do you use an PWM controller? When your panel maximum power voltage is close to 13volts like tiny foldable portable panels. OR you are very very very poor - MPPT controllers are a lot more expensive than PWM. You can get a good PWM for $25. A good value MPPT will cost $80, but $180++ is more realistic.

I have read here about some setups and recommendations that show a good understanding. I only wanted to put in some practical context.