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Possible 400w solar sys for RV

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stu

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I am getting ready to install a solar sys on a 5th wheel (28ft) I just bought and need some input. I am not a full timer and am usually boondocking a couple times a month. From what I gather from listening to Will’s videos I have come to the following conclusions and want to see if I am on track. My goal is to have 100ah battery, 400w of solar and a 2000w inverter. I thought of going with a 24v sys with a step down converter to 12v just because Will said the components are less expensive. I just sold a boat that had 225w of solar and that was fine for us in the summer but not in the winter so I think 400w of solar panels would be fine. It also had a 1000w inverter and that just was not big enough.

Battery
Build a 100ah 24v Fortune battery bank
We had a 220ah battery bank on the boat but never used more than 60ah and that was with a 12V refrigerator

Solar controller, 2000w inverter
Use a 24V 2400w MPP Solar unit. Choose this unit because the 12V unit only has a 1000W inverter

Solar Panels
(4) rich Solar Poly 100w panels with 2 panels wired in Series and then the 2 pairs wired in parallel. Choose these panels because of Will's panel comparison video

See any issues? Or recommend something else?

Thanks all, Wayne
 
I am assuming that you are refering to the MPPSolar 2424LV-MSD all-in-one.

Some considerations:
  1. This model has an MPPT operating range of 30 - 80V. The Rich Solar 100W has a Vmp of 18.2V, two in series being 36.4V. You would be operating your all-in-one right at its lower threshold. Will this be a problem? I don't know.
  2. All the MPPSolar all-in-ones have terrible no-load quiescent drain, this one being the worst at "<50W" (meaning 49.9W!) That's a 5th of your array just being continuously lost to heat. Nobody wants that.
  3. This model supports up to 2,000W arrays, which just means that you are buying spec you don't need.
Personally, I would just get a small good quality SCC like the Victron 75|15 and inverter like the Phoenix (up to 1,200W) or Phoenix Compact (up to 2,000W). If you can muddle through with 1,200W both devices could be delivered for less than $500.

p.s. No load quiescent draw on the Phoenix 24|1200 is 5W - totally different ballpark.

Edit: added postscript, corrected typo.
 
Last edited:
Thanks tictag, I did not realize the MPPSolar had such a big no-load quiescent drain.
 
ALSO if you are going to go from 24V to 12 for an RV make sure you get a 24V to 13.8V ... 24V to 12V will underpower most RV lights and motors and pumps ..

Amazon.com: New Big-Size Voltage Converter Regulator DC/DC DC 24V Step-Down to DC 13.8V 40A 552W Buck Transformer Waterproof : Electronics

Buy New Big-Size Voltage Converter Regulator DC/DC DC 24V Step-Down to DC 13.8V 40A 552W Buck Transformer Waterproof: Car Electronics - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
 
tictag said:
I am assuming that you are refering to the MPPSolar 2424LV-MSD all-in-one.

Personally, I would just get a small good quality SCC like the Victron 75|15 and inverter like the Phoenix (up to 1,200W) or Phoenix Compact (up to 2,000W). If you can muddle through with 1,200W both devices could be delivered for less than $500.
Click to expand...

TOTALLY agree that 2424LV is a hog that should only be used in sheds somewhere in Texas/Arizona desert with plenty of room for extra panels just to power the loss ...

AS for my favourite setup for RV I like the EPSOLAR 40A pushing to 24V battery setup with a 24V 1500W GoPower inverter - and then a https://www.amazon.com/gp/product/B07D7MVZGP/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1 13.8 stepdown to power the RV 12V things ...

I would also mount the EPSOLAR with a spare cable coming out of the input so I could mount some GROUND solar panels that you could carry with you in the trailer and set up on the ground once you get to your location ... for my ground mounted panels I use Anderson connectors because I just hate trying to connect and disconnect those MC-4 -- I can never either find that damn little tool or bird nose when i need it and the Anderson allows me to connect and disconnect in seconds ...
 
Hi, I am here in the U K not as lucky with good weather for solar systems but here is my experience over many years and now selling
systems part time in my retirement. If you are camping off grid we call wild camping a 12 volt system is good for a short period and very
reasonable priced. If you go for a 24 volt system you will have more power to charge your battery bank and run a higher wattage inverter
to save starting up a generator. MPPT charge controllers operate better with hgher voltage panels especially in overcast weather conditions.
24 volt systems use thinner cables so you save money and there is much less heat generated in the cables making it safer than a 12 volt system.
24 volt to 12/13.8 volt step down converters work well for all your 12 volt components but you must isolate to stop drain on the battery bank.
In good weather conditions a 24 volt system will charge your battery bank quickly and when full you can divert power directly from your solar array
to an ac water heater via the inverter to have free hot water or run a low wattage air con unit.
 
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ghostwriter66 said:
ALSO if you are going to go from 24V to 12 for an RV make sure you get a 24V to 13.8V ... 24V to 12V will underpower most RV lights and motors and pumps ..

Amazon.com: New Big-Size Voltage Converter Regulator DC/DC DC 24V Step-Down to DC 13.8V 40A 552W Buck Transformer Waterproof : Electronics

Buy New Big-Size Voltage Converter Regulator DC/DC DC 24V Step-Down to DC 13.8V 40A 552W Buck Transformer Waterproof: Car Electronics - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
Click to expand...
THANKS, I did not realize that
 
ghostwriter66 said:
TOTALLY agree that 2424LV is a hog that should only be used in sheds somewhere in Texas/Arizona desert with plenty of room for extra panels just to power the loss ...

AS for my favourite setup for RV I like the EPSOLAR 40A pushing to 24V battery setup with a 24V 1500W GoPower inverter - and then a https://www.amazon.com/gp/product/B07D7MVZGP/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1 13.8 stepdown to power the RV 12V things ...

I would also mount the EPSOLAR with a spare cable coming out of the input so I could mount some GROUND solar panels that you could carry with you in the trailer and set up on the ground once you get to your location ... for my ground mounted panels I use Anderson connectors because I just hate trying to connect and disconnect those MC-4 -- I can never either find that damn little tool or bird nose when i need it and the Anderson allows me to connect and disconnect in seconds ...
Click to expand...
Why do you prefer the EPSOLAR 40A over the Vicron? And what model EPSOLAR there seems to be two 40A models. Thanks
 
I don't know why it's so popular to buy 4 or more 100 watt panels, when there are panels available that deliver substantially more power and at a less expensive per watt price. Seems to me, one is better off buying two 250 watt or 335 watt panels. More power, less expensive, less wiring, less mounting hardware needed etc. Am I missing something? Maybe, because they may be lighter and smaller?
 
DASH said:
I don't know why it's so popular to buy 4 or more 100 watt panels, when there are panels available that deliver substantially more power and at a less expensive per watt price. Seems to me, one is better off buying two 250 watt or 335 watt panels. More power, less expensive, less wiring, less mounting hardware needed etc. Am I missing something? Maybe, because they may be lighter and smaller?
Click to expand...
Will in his book says this; "Smaller solar panels are inherently stronger and thus, recommended if you mount them on the roof of a moving vehicle. 100W panels are the best size. They are strong, cheap, easy to find and easy to install." And another thoughts is redundancy. If you lose on 335w panel you done. If you lose one 100w panel you will still have 3 panels. thanks for your input
 
stu said:
Will in his book says this; "Smaller solar panels are inherently stronger and thus, recommended if you mount them on the roof of a moving vehicle. 100W panels are the best size. They are strong, cheap, easy to find and easy to install." And another thoughts is redundancy. If you lose on 335w panel you done. If you lose one 100w panel you will still have 3 panels. thanks for your input
Click to expand...
Good Points. I guess, I'm a little bit spoiled, Santan Solar is about 20 miles from here so I went with the big panels.
 
stu said:
Why do you prefer the EPSOLAR 40A over the Vicron? And what model EPSOLAR there seems to be two 40A models. Thanks
Click to expand...

choosing EP vs VIC is mainly due to price ....

Here is my go to .... you can find it much cheaper -- just wanted to find something for you to look at ... https://www.amazon.com/Fuhuihe-EPEV...1&keywords=epsolar+40a&qid=1594087041&sr=8-30

Get the MT50 programming module -- OR you can do it via laptop with a very cheap cord .... I use the MT50 as a remote monitor ....
 
DASH said:
I don't know why it's so popular to buy 4 or more 100 watt panels, when there are panels available that deliver substantially more power and at a less expensive per watt price. Seems to me, one is better off buying two 250 watt or 335 watt panels. More power, less expensive, less wiring, less mounting hardware needed etc. Am I missing something? Maybe, because they may be lighter and smaller?
Click to expand...

So on our trailers at work we shoot for 200-300 W panels ... they are just as strong as the 100W -- there are less holes to drill -- less cabling ... and in over 3 years of doing this at work we have never lost a panel yet ... also from a cost savings you can get bigger panels cheaper per watt than smaller ... I know Will said that - but many of us on here would argue that ... YES i would NOT put a 500 WATT'R on top but I would choose a 250-300 before 3x100 any day of the week ...
 
I have the issue of limited real estate on top of my van. I have room for two 100 W panels or one 300 W panel. I am going for a single 300 W panel.
Plus a single panel makes designing a tilting mount one heck of a lot easier to do. I was thinking about it today, and I thought of a way to do a 4 way tilting mount.

The Renogy 300W Monocrystaline panel was the most compact unit I could find. 65" x 39" will fit easily on my van (I have a luggage basket on the rear half of my roof).
 
Stu, in my RV 100 Ah isn't much. I'm currently running 225 Ah of flooded lead acid batteries. I have to be quite stingy in my power usage since I effectively have only about 112 Ah.

I'm shooting for 560 Ah so I don't have to worry about the power. I like to make a couple cups of coffee, turn on all the lights, run the pump and take a shower, run the radio and charge up all the electronic devices. There there is the furnace if it's cold.
 
HRTKD said:
Stu, in my RV 100 Ah isn't much. I'm currently running 225 Ah of flooded lead acid batteries. I have to be quite stingy in my power usage since I effectively have only about 112 Ah.

I'm shooting for 560 Ah so I don't have to worry about the power. I like to make a couple cups of coffee, turn on all the lights, run the pump and take a shower, run the radio and charge up all the electronic devices. There there is the furnace if it's cold.
Click to expand...

Thanks HRTKD, I just sold a boat where I also had 220AH of flooded lead acid batteries and a 225w solar panel. And ran a 12v refrig and had no issues in the summer. My boat was heated by a propane fireplace that only had a computer fan so not much power there. So the heater on an RV is a consideration I need to take into account. I am also in California and most if not all my RV'ing will be in Cali. I figured by upping my solar to at least 400w and having a propane frig I think I would be find with a 100ah 12v Lith battery. If not I can also add for cells. Still deciding whether to go 12v or 24v. This is a pretty small setup so not sure going with 24v will actually save me much if anything. thanks for your input
 
stu said:
Thanks HRTKD, I just sold a boat where I also had 220AH of flooded lead acid batteries and a 225w solar panel. And ran a 12v refrig and had no issues in the summer. My boat was heated by a propane fireplace that only had a computer fan so not much power there. So the heater on an RV is a consideration I need to take into account. I am also in California and most if not all my RV'ing will be in Cali. I figured by upping my solar to at least 400w and having a propane frig I think I would be find with a 100ah 12v Lith battery. If not I can also add for cells. Still deciding whether to go 12v or 24v. This is a pretty small setup so not sure going with 24v will actually save me much if anything. thanks for your input
Click to expand...

I have 150 watts of solar and the propane fridge. I can be 100% charged at the end of the day. But the batteries just don't last long enough through the night when it's cold. If you never have to worry about the cold, you're probably OK.

I'm sticking with 12v to keep things simple. 24v complicates the design and raises the cost because I would have to replace/add so many other components (12v converter has to be 24v, alternator charging requires a step up DC-DC charger, existing inverter probably can't handle 24v). The lure of 24v isn't enough to counter all the additional cost and effort.
 
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