View Full Version : Bighorn Solar Install

05-04-2015, 08:48 PM
A couple of members have asked me to post my solar install blog here on the forum. The link below will take you to my Bighorn Solar Install. My system is 820 watts with 672 amps of storage. The system is pretty much straight forward for a solar install. I have several photos and sort of a step by step process as to how I did things.

The write-up > Bighorn Solar Install (http://bighorn3570rssolar.blogspot.com/)

05-04-2015, 10:13 PM
Wow! Very nice install. Lots of power too!

'Lil Guy'
05-05-2015, 04:12 AM
To start with, I know squat about solar power. What is the reason for all of the batteries? Is it to store power? Lots of weight there to carry. How do they work when hooked up to shore power? Forgive all the questions here but just curious and have no clue about using solar power. Seems like it would be great for dry docking. Just seems like those BH's are made to be parked and plugged in. Again, are those batteries also used with shore power? Love to catch you at a rally so I could see this set up live and get some 1st hand lessons on how it works. Looks like you know what you're doing with that clean set up.

05-05-2015, 07:21 AM
Really neat and professional looking. Your write up wasn't to shabby either. As someone not versed in solar, I found it easy to read and understand. One question that I didn't see an answer to, was any idea of the total weight added for the whole system?

'Lil Guy'
05-05-2015, 07:37 AM
I guess I should have read the write up (I didn't notice it) before my post. Again, a clean looking install.

05-05-2015, 09:34 AM
I just read the write up from the link at the bottom of post 1. Again I say WOW!. What a well thought out, clean and well executed install and amazing write-up. Thanks again for sharing.

05-05-2015, 09:51 AM
The batteries weigh 65 lbs each (390 lbs). About 110 lbs more than a 5500 Onan generator. The inverter is about 50 lbs. The other components in the bay weigh about 15 lbs. not counting the converter. The panels weight about 26 lbs each (156 lbs). Then your guess is probably as good as mine about the weight of the wire and cables, maybe 50 lbs.
The batteries weight is similar to Trojan T-105s at 62 lbs each. The total system weight probably is about 320 lbs more than an Onan Generator. So when you think about added weight it can boil down to the benefits and how you rationalize it out.

baker, I got a chuckle along with you thinking about how all those big blue batteries look in the front bay. The photo makes them look over powering for the space.

jbeletti, Thank you for your kind words. My purpose was to share my solar install for the Bighorn as I did with my previous rig. Lots of folks here on the forum have successful solar installs using different installation methods. For anyone interested in solar one can probably find answers to any questions they have right here on the forum.


05-05-2015, 12:19 PM
A couple of members have asked me to post my solar install blog here on the forum. The link below will take you to my Bighorn Solar Install. My system is 820 watts with 672 amps of storage. The system is pretty much straight forward for a solar install. I have several photos and sort of a step by step process as to how I did things.

The write-up > Bighorn Solar Install (http://bighorn3570rssolar.blogspot.com/)

I assume you mean 672 Amp-Hours at 12V is stored? or about 336 Amp-Hours @ 12V useable. All using a 25 Amp rating.

05-05-2015, 12:50 PM
You are correct 672 Amp-Hours stored. Considering depleting the batteries to no more than 50%, that would be 336 Amp-Hours of usable Amp storage. The 224 amp capacity for each battery is based on 20 hour rate. I have read that the AGMs can be drawn down more than 50%. I am not sure that would be a good practice. This is my first go with AGMs.

05-05-2015, 02:01 PM
Thanks for the web page. It looks great and should prove very useful.

05-05-2015, 02:04 PM
This is what it would have looked like to go Li Ion. $3600.00, ouch, but you would never replace then.


05-07-2015, 08:15 AM
Very nice install.

05-07-2015, 07:02 PM
I see those batteries for about $280.00 each. Is that about right? Or $1,700.00 for the six? Plus delivery.

05-07-2015, 07:33 PM
They were right at $250 each with a trade in of 4 cores. No Tax because they were a solar item. No shipping since I picked them up on the way through Quartzsie. I went with the Fullriver DC224-6s because of their common availability. Most all other sizes would have had to be ordered. My AGMs came from Discount Solar in Quartzsite. DC224-6s were their most popular sellers, they had pallets of them on the floor. I checked with several places and they offered the best price. Two L16s were more attractive in some respects but availability was an issue. Like with about any battery you choose to use you have to choose the best price in your area and availability if you do not have them shipped.

05-07-2015, 09:50 PM
What a beautiful install. I found the write up extremely timely since i had been doing serval hours of research on solar panels. I was wondering about your statement that if you started from scratch you would consider using the larger panels today. I see that there are 260 and 340 watt panels at voltages in the 30-40 volt range. My question is in your opinion are the larger sizes too delicate to handle the bumps and abuse that traveling on the highway causes. I see that you also are using 6 volt batteries why 6volt? I have seen some nice 12 volt AGM' by Trojan. Last question had you considered making the convertor switch on and auto disconnect the batteries when connected to shore power. I am trying to cover all the bases before staring my project.

05-07-2015, 11:53 PM
You are asking some very good questions. I will give you my answers which can always be subject to differing opinions. But they are my humble answers.

1. Larger panels are not necessarily more delicate than the smaller panels. I can't speak for all panels of different brands. But most I have observed would have no problem if mounted properly. You have choices for mounting also. A rail system for a single or multiple panels to mount to can act as a stiffener if needed. In addition to a mounting bracket in each corner, an additional bracket can be mounted mid way along each side to help stiffen the panel frame. Sometimes the roof real estate for lack of a better term dictates how the panels will be mounted. Usually using rails two panels or more will mount on or to them. There are very elaborate rail systems available, but can be costly. Rails can be made from aluminum stock available at some home supply outlets and especially metal supply places. Individual mounting brackets are in plentiful supply if you do not make your own.

2. 6 Volt batteries choice. This is one of those things where there is always a debate and facts get skewed slightly to further the debate of each and there is never a winning argument to be had. I used 6 volt batteries because of availability and in my circles and studies I have made are seemingly more popular. Most of the real serious solar installs I know of use 6 volt batteries. This statement is not to besmirch anyone making the choice to use 12 volt batteries. There is nothing wrong using 12 volt batteries.
Weight for the Fullriver batteries were about the same for the equal amps for each bank. 6 volts 6 batteries 672 amps 390 lbs. 12 volts 3 batteries 645 amps 396 lbs. Length of space 6 volt and 12 volt within 3/4" of each other. 6 volt 7" deeper in depth. 12 volt 4" more in height. The footprint of total space for the 12 volt bank would be about 1/2 that of the 6 volt bank. The point of the battery choice is to get a true deep cycle battery which is not the same battery as a marine rv battery.
My previous rig had 4 6 volt Interstate U2200 golf cart batteries which are commonly known as lead acid or flooded cell batteries. They were five years old and still going strong when I traded them in as cores for the AGMs. So I had good service from 6 volt batteries and had no problem using them again. As stated previously my AGMs came from Discount Solar in Quartzsite AZ. During the season they sold hundreds of the DC224-6s and they were their most popular seller.
I am not trying to make a case that 6 volt batteries are the best or only way to go. I am simply stating my case why I used them.

3. Regarding the auto disconnect for the converter you speak of, I am not familiar with it. Actually I am not sure you would need to spend the money on one. What I have found is the solar in the past has always kept my batteries charged and the converter is not needed. My previous rig had the converter unplugged and not even hooked up to the batteries. I doubt I will need to use the converter. I could use a 15 amp outlet to power the converter independently from the coach and at the same time use the inverter to power the coach circuits. Or use the Honda to run the converter while using the inverter for coach power. I moved the converter to the front bay to simplify plugging it in if I wanted to. I made up a short extension cord with a 20 amp female plug end to hook to the converter because the converter has a 20amp male pigtail. I think most people just unplug the converter and forget about it when they have a functioning solar system.

Steve it is good you are doing your homework researching solar panels and probably other solar systems requirements. There are many sites out there that are very helpful. Several folks here on the forum have systems that serve them well and are well installed. Most all are probably different from the next one. The goal is to have an efficiently well working system. If you have not visited Jack Mayer's site, I would recommend doing so. Jack has a information packed site. Not so many photos.
I wish you the best with your solar project. Joe

05-08-2015, 12:14 PM
I see you have both the original converter and the inverter/charger in the circuit at the same time. It looks like they have separate AC sources. Why are both still there. What is the source for your converter? How do you use them? Do you use both at the same time? How does that work? How do they interact with the solar charger? How do they all effect the three stage charging system in each other?

05-08-2015, 01:52 PM
The converter is connected to the DC Positive and Negative power hubs. You can not use the charger in the inverter at the same time you are using the inverter. The converter is unplugged and disconnected from the coach power and must be plugged into an external power source like an extension cord when using the inverter. If it were plugged into the coach power circuit you could possibly damage equipment, drain batteries and maybe have a bad case of smoke. The inverter has pass through power when plugged into shore power.
There are several reasons for having the converter available for use if needed. If you have an inadequate shore power supply, you can use the inverter for coach power and use the converter to charge the batteries at the same time. If the inverter goes out or there is a solar system failure you can charge your batteries.

Let's not get hung up with the converter. As mentioned in the previous post, with my last system the converter was unplugged and forgot about. The solar charging kept the batteries charged. I could foresee several days of clouds and rain and the batteries might need some charging. The Honda 2000i or an extension cord to external power could come in handy to power the converter. Most folks unplug the converter and forget about it when they have a functioning solar system.

To answer the charging question, the charge controller goes into float and the converter shuts down when the batteries are charged. I am just simplifying the answer without getting into a long post.