Proposed Solar Setup

[MIBobS]

All,

I just wanted to run by my thoughts on what I am thing about for our 5th wheel (see attached pic of my proposed layout).

This to be able to Boondock on our 2 month trip out west moving about every 4 to 5 days.

My energy audit said to plan on using 75 to 90 Ah a day depending on TV/Satilight usage and temperature. We have Boondocked in the past but only for 3 to 4 days with no solar and just 3 12v marine batteries so we know how to conserve but we aren't looking to "ruffing it this trip.

I already have the Renogy 600watt mono off grid Kit.

Thx in advance.

[MIBobS]

Updated layout with some suggested changes and more clarification.

[bkrahn]

Looks like a good set up. Just have a question. What size is your battery bank?. I would also wire the solar panels direct to the batteries so they charge even when the disconnect is off. I have installed allot of systems. My last system had 2 160 watt solar panels, 4 6 volt batteries and a 2000 watt inverter all hard wired in an Outback trailer. They needed to run a CPAP machine for 8 hours a night while dry camping. They are very pleased with the whole system. The biggest issue is how often you plan to use 120 volt appliances.

[bkrahn]

Okay just noticed the updated picture you posted. Do you have the room on your roof for 6 100 watt panels? Also you will have to wire those panels with at least 8 gauge wiring as they can produce over 30 amps. I am not familiar with renogy batteries but personally I would go with 4 or 6 6 volt batteries as they have much thicker plates and can handle the large discharge rates from an inverter better than 12 volt batteries. If you have the room for those batteries that is. What I usually suggest to my customers is start smaller first and if you need to you can add more later. So wire the coach for 6 panels but try using 4 at first. Adding 2 more panels later is fairly easy if you need to.



Cheers

[MIBobS]

Originally Posted by bkrahn

Okay just noticed the updated picture you posted. Do you have the room on your roof for 6 100 amp panels? Also you will have to wire those panels with at least 8 gauge wiring as they can produce over 30 amps. I am not familiar with renogy batteries but personally I would go with 4 or 6 6 volt batteries as they have much thicker plates and can handle the large discharge rates from an inverter better than 12 volt batteries. If you have the room for those batteries that is. What I usually suggest to my customers is start smaller first and if you need to you can add more later. So wire the coach for 6 panels but try using 4 at first. Adding 2 more panels later is fairly easy if you need to.



Cheers

Thx bkrahn for your response and suggestions. I checked the roof and I have room for up to 8 panels. And yes 8 gage wire is what came with the panel kit. Thx again for taking the time to look my plan over.

[RoadDogYVR]

Originally Posted by bkrahn

. Do you have the room on your roof for 6 100 amp panels?

Hey bkrahn, you may want to edit your response for accuracy and change 100 amp to 100 WATT in this instance.

And thanks for responding as I'm actively reading whatever I can in anticipation of making my own coach upgrades.

[bkrahn]

oops.....typo haha


those would be some huge panels !!

[RoadDogYVR]

Originally Posted by bkrahn

those would be some huge panels !!

I could use some... but then I'd need to come on here and ask if my tow vehicle could handle the extra weight and we all know what a kettle of worms THAT opens up...

[R.B]

Two things I see:

1. Most inverters want a pretty large fuse. I have a 400A fuse on a 3000VA inverter, so your 250A breaker may not be enough and trip early.

2. Consider how you’ll prevent the inverter from powering the AC panel and then flowing right back into the DC charger. Manually shutting off the breaker? Wiring the charger upstream of the input switcher?

[John Hilley]

I would put a switch in the panel output to charge controller. DC should be applied to charge controller before solar.

[creativepart]

I haven't checked the specs on that converter or on that inverter. But it looks like good stuff for everything else. If it was me designing this system, and it's not, I'd replace the converter with a better brand inverter/charger - like a Victron or Magnum.

Most converters don't have significant charging amperage to quickly recharge a larger battery bank. Your's might, but I haven't checked the specs on it.

A Magnum 2800w Hybrid Inverter/Charger will do a great job of meeting your needs from what you describe. I realize it costs more - but you can easily add a Battery Monitor Kit and an Auto Gen Start feature to the Magnum for not much money and really tailor the system to meet your needs.

I have 3-100 watt panels, a PWM 30-amp charge controler, 4-12v true deep cycle AGMs, an Auto Gen Start on our 5.5K generator and a Magnum PSW 2000w inverter/charger. Much of it came with my RV because I have a residential fridge. All I had to do was add 2-100 panels. We don't Boondock a lot in our 38' Class A, but when we do we have no issues with power at all.

[MIBobS]

Originally Posted by R.B

Two things I see:

1. Most inverters want a pretty large fuse. I have a 400A fuse on a 3000VA inverter, so your 250A breaker may not be enough and trip early.

2. Consider how you’ll prevent the inverter from powering the AC panel and then flowing right back into the DC charger. Manually shutting off the breaker? Wiring the charger upstream of the input switcher?

The PS converter/charger will be on the L2 side of the breaker box (only powered with Shore Power). Transfer swith only powers L1 side when in Solar and powers both L1 and L2 when in Shore Power.

[MIBobS]

Originally Posted by R.B

Two things I see:

1. Most inverters want a pretty large fuse. I have a 400A fuse on a 3000VA inverter, so your 250A breaker may not be enough and trip early.

2. Consider how you’ll prevent the inverter from powering the AC panel and then flowing right back into the DC charger. Manually shutting off the breaker? Wiring the charger upstream of the input switcher?

On number 1), one of the references I used said a 400 amp fuse or a 250amp DC breaker, I will double check thx.

[hclarkx]

You are planning my system almost exactly. The only differences being a 300AH LFP battery and a 900W inverter in mine. I don't run A/C and my Panasonic microwave needs as little as 416W (lowest several settings) and expresso maker and toaster are around 900W so the 900W inverter is fine.

Some things to be aware of ......

1) You have 600AH of battery so are probably okay here, but it's easy to trip the inverter on low voltage when a lead acid battery gets down around 50% charge. And when the batteries have aged, this problem is worse. Be sure your Renogy batteries will supply the highest inverter current you expect to have at a voltage that your inverter will accept (when the batteries are down around 50% charge).

2) Take into account that you need to multiply your daily AH use by about 1.2 to get the actual AH that must be provided by the battery. The added 20% becomes battery internal heat. A proper battery monitor will take this into account. On top of this, there are also battery internal losses during charging. If battery internal losses are 20% each way, the solar systen needs to produce about 44% more AH than you use to cover them. You can probably get data from Renogy on losses though estimating them is tricky because the losses vary with the square of the loading and generator current (I squared R) so vary from minute to minute.

4) You mention temperature; I suspect you are thinking propane heater fan running time. Keep in mind as well that lead acid batteries are crippled a bit by low temps (less AH available). Renogy should have information on this.

5) Finally, the general rule is to not take lead acid betteries below 50% charge for long life. Reducing depth of discharge from 50 to 30% increases battery life by 200% or more. Hence a 67% larger battery may get you 250% more life if you are discharging to 50%. In your case, your 90AH or less out of about 240 AH available (80% of 50% of 600AH) means you will typically be well under 50% (assuming daily recharge to 100%). I think you are fine here. See a lead-acid battery cycle life curve here: https://www.bing.com/images/search?v...=20&ajaxhist=0

For reference, my 600W system works great on our typical 5 day stays. I use 60-70 AH per day. I always get back to 100% if it's mostly sunny and, if it's winter, the sloping roof of my 5er is facing south. But, as I noted above, I have an LFP so don't need as much AH from my solar as you will. For your higher AH use and having LA batteries, I'd suggest increasing your solar to 800W if that's workable. Or maybe allow for a future 800W in the conroller. Though with 600W you won't be using the generator all that much and mainly in the a.m. to help with the bulk charge (where a generator is effective and running time is tolerable).

There's my FWIW 60 cents worth. Hope it helps though I think your are good to go. Good luck. If I wasn't clear on anything, please ask.