Recommendations for an 80 watt off road ready vehicle Solar Panel?

[Rezarf <><]

I would just get a Renogy 80watt hard panel. I just installed 29 285watt panels on my house. After months of research I'll say this. Most solar panels sold to the adventure types with fancy branding are massively over priced and really nothing special. Get a Renogy panel and call it good.

Something like this?

http://www.amazon.com/Renogy-Watts-...ie=UTF8&qid=1456346876&sr=8-5&keywords=renogy

 

[calicamper]

Something like this?

http://www.amazon.com/Renogy-Watts-...ie=UTF8&qid=1456346876&sr=8-5&keywords=renogy

Not sure how good that controller is or how easy it is to use.

Do you need a controller? Wasnt sure if you had one yet?

I have this one works great no issues nice features etc. Easy to use. If your not using the power out feature turn the mode to "CH" the 24hr power on to the output side does create a parasitic draw when turned on.

But the charge management has been great.

http://www.amazon.com/gp/aw/d/B013H...6_SY340_FMwebp_QL65&keywords=solar+controller

Panel
http://www.amazon.com/gp/aw/d/B009Z...olar+panel&dpPl=1&dpID=41rOZxjogoL&ref=plSrch

 

[4x4junkie]

Here is an explanation of power needs I copied from another thread from Mario at AT.

"Measuring consumption on an Engel 45 at our shop using a "Doc Watson" from www.powerwerx.com, we have seen daily consumption of 20 to 28 A/h per day at 12 VDC on the "Ref" setting (around 38-40F) with ambient temps is the 70-80F range. Our experience with solar panels is that unless they are mounted on a tracking system, perfectly aligned for latitude and the season, the weather is cool and the sky is un-obstructed by clouds, we can only expect 70% performance. This means for example that a 100 watt panel will only produce 70 watts per hour. This means 5.8 A/h rather that the rated 8.33 A/h @ 12 VDC.

So...if you were to back into the consumption of an Engel 45 you would need 60 to 80 watts of PV based upon 20 to 28 A/h of consumption per 24 hr period for a PV to keep up with your needs on the "Ref" setting on the MT-45.

The 22.5 W panel per our calculations will produce as follows: 22.5W/12VDC = 1.875 A/h x .7 = 1.312 A/h x 6 hrs of average usable sunlight = 7.85 A/day ( 6 hours is based upon information from sources such ashttp://www.energyatlas.org/contents/default.asp). Considering that your draw is 20 to 28 A/h per day, you will be coming up short 12 to 20 A/h short with 22.5 watts.

I know this is a lengthy explanation but is is based upon Ohms law:
Watts / Volts = Amps. As in all equations, you can flip this around such as Amps x Volts = Watts etc. Throw in the factoring of .7 to the PV for performance and you will not be disappointed.

Based upon these formulas and numbers, we supply 80 watt panels to our trailer customers who express a desire to be "self contained" with their fridges and laptops for indefinite periods. The calculations have been successful to date. (emphasis added by me)

I hope this will help you in your solar endeavors."

The flaw in that is that it doesn't offer a reserve for when the weather turns warmer than "70-80F range".
At 90°F, a fridge set to 38°F will likely draw around 40-45% more energy than it will at 75°F. So the 28Ah consumption figure will become closer to 40Ah, all while the panel becomes less efficient due to it being hotter too. There is also the inherent power loss that occurs with putting energy back into a lead-acid battery that needs to be overcome as well.
Additionally the 70% solar performance expectation he states is a bit optimistic. Facing directly at the sun at high-noon, you already can expect a panel to only produce 75-80% of it's rated power output if you use a PWM type solar controller (the most common type), so you have to apply all those factors after also deducting the 20-25% loss due to the PWM controller. So in reality you're looking at something closer to around 55% for performance efficiency (if you use a MPPT controller, then this extra loss is only about 3-5%).

This is why my minimum 120W solar recommendation, to have a little bit of reserve built into your system.

If you seldom venture out when it's warmer than 70°F (or you typically have very cool nights), and/or you will be running the engine at some point while camped, I would agree then that 80 watts will probably be fine.

 

[plh]

Not sure how good that controller is or how easy it is to use.

Do you need a controller? Wasnt sure if you had one yet?

I have this one works great no issues nice features etc. Easy to use. If your not using the power out feature turn the mode to "CH" the 24hr power on to the output side does create a parasitic draw when turned on.

But the charge management has been great.

http://www.amazon.com/gp/aw/d/B013H...6_SY340_FMwebp_QL65&keywords=solar+controller

Panel
http://www.amazon.com/gp/aw/d/B009Z...olar+panel&dpPl=1&dpID=41rOZxjogoL&ref=plSrch

I think this is the same controller for a little less money:

http://www.amazon.com/dp/B014Y7S132

Are the USB output ports 1A each on yours?

 

[1Louder]

I agree more watts are better but I am comfortable with the 80 watt rating that Adventure Trailer recommends, they research, test and know their stuff. I wouldn't balk at a higher powered panel I just don't need to over build everything, I view this panel as a way to top off the secondary battery while at camp. I hope that helps a little.

I look forward to seeing your design. I would like to do something similar.

 

[Titanpat57]

Believe it or not Home Depot has some interesting prices on panels, of various sizes.

I just finished up an aluminum rack design for the new 4runner...and I'm looking to mount one over the moon roof that will hinge in the front, and can be adjusted to tilt up in the back.

The only thing I haven't nailed down is a decent MPPT controller.

 

[calicamper]

I think this is the same controller for a little less money:

http://www.amazon.com/dp/B014Y7S132

Are the USB output ports 1A each on yours?

I dont use them not sure. I have a simple 12v hub I put a plug on and just set that up. We can charge 4 usb dohickies and it has two 12sockets on it. Though havent used the sockets yet. But figured I might use some car type device with a socket so bought it.

 

[IdaSHO]

FYI, for those on a serious budget that also feel the need for MPPT, check out the EcoWorthy 20Amp unit.

http://www.eco-worthy.com/catalog/worthy-mppt-solar-charge-controller-12v24v-p-182.html

Ive been running it in my custom camper for nearly a year now with no problems.

Seems to be one hell of a deal IMO, and on par with units that cost north of $400 or $500

 

[plh]

FYI, for those on a serious budget that also feel the need for MPPT, check out the EcoWorthy 20Amp unit.

http://www.eco-worthy.com/catalog/worthy-mppt-solar-charge-controller-12v24v-p-182.html

http://www.amazon.com/ECO-WORTHY-Charge-Controller-Regulator-15-30/dp/B00FF1KGT4

I've heard they are good units, but have also read that they are not MPPT. I do not know anything first hand about them so take it FWIW. Also you don't get any advantage with MPPT and may be worse charging then with PWM on a small system like 80 watts (or even 150 watts for that matter).

I have a SunYoba T40. Mine is labeled as MPPT (some are - some aren't)- I know after reading reviews before I bought it its is not and is actually PWM. I like it because I can program charge voltages. I won't recommend it - I'd say its average in a large pool of choices.

http://www.amazon.com/Sun-YOBA-Regulator-Controller-Three-time/dp/B00WFZQC4Q/

 

[IdaSHO]

http://www.amazon.com/ECO-WORTHY-Charge-Controller-Regulator-15-30/dp/B00FF1KGT4

I've heard they are good units, but have also read that they are not MPPT. I do not know anything first hand about them so take it FWIW. Also you don't get any advantage with MPPT and may be worse charging then with PWM on a small system like 80 watts (or even 150 watts for that matter).

I have a SunYoba T40. Mine is labeled as MPPT (some are - some aren't)- I know after reading reviews before I bought it its is not and is actually PWM. I like it because I can program charge voltages. I won't recommend it - I'd say its average in a large pool of choices.

http://www.amazon.com/Sun-YOBA-Regulator-Controller-Three-time/dp/B00WFZQC4Q/

The ecoworthy unit is most certainly an MPPT

I have the amperage reading to prove it.


I routinely see 14+ amps @ 12v from two 100W 24V panels

They are rated at 2.88 amps each

 

[4x4junkie]

Also you don't get any advantage with MPPT and may be worse charging then with PWM on a small system like 80 watts (or even 150 watts for that matter).

MPPT will always offer an advantage over PWM on a system that is set up correctly. MPPT's advantage actually becomes greatest on cloudy/overcast days when the panel tends to be cooler (a panel's Vmp point changes inversely with temperature quite significantly, something that would be of little relevance with a PWM controller).

I would agree however that the value in MPPT tends to be less on small systems, but MPPT indeed will deliver more juice from the panel(s) to your battery regardless of system size.

 

[goodtimes]

I agree more watts are better but I am comfortable with the 80 watt rating that Adventure Trailer recommends, they research, test and know their stuff. I wouldn't balk at a higher powered panel I just don't need to over build everything, I view this panel as a way to top off the secondary battery while at camp. I hope that helps a little.

I think they're recommendation is pretty accurate.

I had a 100w panel permanently mounted on the roof of my camper coupled to a single 105ah AGM house battery. With moderate use of LED lights, an ARB fridge set to 38*f (actual), and minor/intermittent phone/camera battery chargers, I never ran out of power. In fact, I stopped connecting the house battery to the truck charging system all together.

I could see the load from the house battery as soon as the sun hit the panel, & could watch it climb as the sun climbed in the sky (as you'd expect). Once mid-morning rolled around, the load would start dropping off (indicating that the battery was reaching a decent state of charge). By mid day on sunny days (mid/late afternoon on overcast days), the load from the panel was very small, indicating a near full charge. Remember, this is without any connection between the truck charging system and the house battery - so if you're moving every day or three, you're in even better shape despite having 20% less panel.

If your house battery is hooked to the vehicle charging system & you're moving nearly every day & only want the solar to make up a bit for the one day that you may not move - 80w is fine.

If I expected to spend a lot of time with dirty panels, or in the shade, or in a lot of heavy overcast/rainy days, then combine that with not starting the vehicle every couple days, I'd consider more panel.

 

[Rezarf <><]

Goodtimes, what do you use to monitor the loading and discharging of the system?

Also, could anyone give me a short Lyman's breakdown of the differences and or advantages of MPPT vs. PMT?

 

[AndrewP]

You need a power meter. About $20 on Amazon. When you put it inline with your system, you know your loads, cumulative power and current voltage.

Like this:
http://www.amazon.com/gp/product/B0...power meter&qid=1456800619&ref_=sr_1_2&sr=8-2


Edit:
If you use a "12 volt" panel which has an unloaded voltage of 18 volts or so and PWM controller is fine, If you use a higher nominal voltage panel, then you will want an MPPT controller. At low power and voltages, there is minimal difference in power output. If you're above 200 watts, I'd recommend MPPT. I don't think the cheap PWM controllers are worth having, but if you're set on an 80-100 watt system, then a Morningstar SunSaver10 will work great and is not expensive.

Read the links in my first post and you'll see.

 

[calicamper]

Some of the solar charge controllers can act as your meter in vs out also, thats how I set mine. Though either way works.

The panel temp thing is a pretty big deal vs power generation. One of the big reasons I didnt put a fairing on my the system on our house. I wanted good air flow under the panels to help keep temps down. Look at some of the setups on the houses they are darn near laying on the asphalt shingle with fairings to boot i bet those panels get smoking hot and see a big hit on production in the summer. Which happens to be a big reason many of us add them to off set Pool Pump costs. LOL