Do-it-yourself Solar Install; Part 1

lvuman

Active member
I recently purchased an early model 2015 Leisure Travel Van, Unity MB model that did not have the solar option. This turned out to be a plus as I was able to over double the factory wattage and hopefully wire it more efficiently. Although new at this, I had tremendous help and mentoring from "Klipstr" on the Sprinter UnityForum and thought I might share the installation and what I learned in the process.

Disclaimer: I'm new at this. Use the information at your own risk. I researched what I could find and asked questions. Hopefully this will be another helpful resource for others wanting to do it themselves.

The "factory solar pre-wire" consisted of a pair of 8AWG wires and a single 12AWG wire running for the control cabinet​ above the entry door ​directly to the battery box. The issue with the factory pre-wiring was the wires sizes were too small and didn't allow for the proper installation of a charge controller close enough to the battery box to prevent voltage loss without installing heaver wire.

Factory pre-wire in the control cabinet:
Solar-pre-wire-#1.jpg

Solar-Pre-wire-#2.jpg

With the help of Kelly Lipp​, I decided to start over. I was able to install 4 Suaoki 100W 18V 12V Solar Panels on my Unity. I would have preferred to have installed ​5 panels but due to a previous installation of a satellite TV cable, I only had room for 4 panels without re-routing the satellite cable to another location. Important: Cut out rectangles of cardboard from the solar panel shipping boxes and temporarily tape them to the solar cells to prevent electrical shock when doing the installation. Leave enough room around the edges of the panels and the RV roof to clean with acetone prior to applying the eternabond tape. Attach your panels as far away as you can from other roof items to prevent shadows on the panels. Even a very small shadow on just a small part of the panel will drastically reduce to current output.

4 panel installation:
Solar-Panels.jpg

I attached the panels, combiner box, and secured the wires with Eternabond 2" tape. I've used Eternabond on my previous class A with great success to seal seams. Once it sticks, it's there for good. It made it a good looking, streamline installation too. (Important: Before ordering any flexible panels, make sure they haven't been subject to a recall.)

2" Eternabond tape securing the panels:
Taping.jpg

I ran all my ​solar panel wires to a combiner box (buss bars purchased at Lowe's) that was attached with eternabond tape to eliminate extra holes thru my roof. I needed to extend some of my solar panel cables to the combiner box. You can make your own cables with extra MC4 panel connectors and a crimping tool, however, it was easier for me to purchase a pair of 8AWG, 10' & 3' pre-made cables with connectors and cut them to the correct length to reach the combiner box utilizing the attached connector. Never used my extra connectors or crimpers.

Combiner box:
Combiner-Box.jpg

Continued on Part #2
 
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lvuman

Active member
Re: Do-it-yourself Solar Install; Part 2

Do-it-yourself Solar Install (continued from Part 1)

Combiner box to roof entry point:
combiner-box-to-roof-gland.jpg

I ran a pair of 6AWG wires from the combiner box thru a 2-wire gland into the top of the tall closet to the left of the entry door (looking from the inside out). I attached it with 6 self-tapping screws and ​sealed it with Dicor self-leveling sealant.

2-wire gland entry point:
Roof-entry.jpg

Upper closet entry (next to control cabinet):
Thru-the-roof.jpg

I installed a 30 amp breaker on the positive, 6AWG wire running to the Bogart Engineering SC-2030 Solar Charger. Important: Leave the breaker open until everything else is connected (pic shows closed)! I would have used a 40 amp breaker if I had been able to use (5) 100W panels. A 30 amp breaker was adequate for my installation.

30 amp breaker:
30-amp-breaker.jpg

The two 6AWG wires continued downward to connect to the Bogart Engineering SC-2030 Solar Charger which was installed about 15" above the floor (close to the battery box). Note: I should have installed the Solar Charger vertically to allow the fins to provide better cooling.

SC-2030 Solar Charger:
SC-2030.jpg

Do-it-yourself Solar Install (continued on Part 3)
 
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lvuman

Active member
Re: Do-it-yourself Solar Install; Part 3

Do-it-yourself Solar Install (continued from Part 2)

After you have installed the Solar Charger, it will be necessary to drill a hole(s) thru the floor then another hole(s) into the side of the battery box to run the pair of 4AWG welding wires to the battery box. I also ran a 4-wire harness from the Tri-Metric TM-2030 Battery Monitor in the control cabinet above the entry door to the battery box at the same time. It's a good idea to install a battery box temperature sensor from the battery box to the SC-2030 Charge Controller at the same time. I mounted the sensor on the inside wall of the battery box compartment. You will also need to drill a hole in the base of the SC-2030 Charge Controller to fit a 4-wire phone cable (goes up to the TM-2030 Battery Monitor in the control cabinet) and the battery temp sensor wire that runs to the battery box.

I installed another 30 amp breaker on ​the positive 4AWG wire ​from the Charge Controller ​to the positive terminal of the battery bank.​ Leave the 30 amp breaker open for now. (pic shows open). Important: Remove the 1 amp fast acting fuse from the B1 (red) wire of the 4-wire harness until all wiring from the Charge Controller to the battery and from the Charge Controller to the Battery Monitor is complete. Attach this 1 amp fused wire to the positive terminal of the battery bank. Install a 500 amp shunt (recommended size) between the batteries on the battery box wall.

Battery box with 2 Interstate 232amp hour batteries:
Battery Box.jpg

Attach a short 2/0AWG battery cable to one of the large bolts on one side of the shunt and the other end of the cable to the negative terminal of your battery bank. Important: There should not be any other wires connected the large bolt on that side of the shunt or to the negative terminal of the battery. Connect all other negative cables (cables to ground, negative 4AWG cable from the Solar Controller, etc.) to the other large bolt on the shunt.


Attach the G1 & G2 wires (2 black wires) from the 4-wire harness to the small Klevin screw on the "load side" of the shunt. The "SIG" wire (white wire) attaches to the Klevin on the "battery side" of the shunt as shown:

500 amp shunt:
Shunt.jpg


Install the TM-2030 Battery Monitor in the control cabinet (or another place of your choosing).

It's not difficult to access the backside of the control cabinet. There are 5 screws to remove the access door. There are 3 screws across the top and a few more at the bottom of the panel to remove it. Most of the electrical connections between the coach and the panel are quick disconnects. I had to clip 2 wires that ran to my water heater temperature controller (on-demand water heater). Other than that, a piece of cake.

I cut the hole for the Solar Monitor with a fine blade jigsaw. It was a little messy as the plastic re-welded itself to the cut but worked ok. Sure there is a better way.

Connect the 4-wire phone cable from the Charge Controller to the phone cable jack on the Battery Monitor. Attach the wiring harness wires from the battery box ​to lugs G1, G2, SIG & B1 on the Battery Monitor. Also, if you choose to monitor a 2nd battery (chassis battery), connect the extra wire from the chassis battery to lug B-2.

TM-2030 installed in control cabinet:
Panel.jpg

Cross your fingers! Remove the cardboard covers on the panels. Install the 1 amp fuse in the wiring harness at this time. The Battery Monitor should light up. Close both 30 amp breakers on the positive wire from the solar panels. It should work great. Mine did.

Here's a list of the Instruction and Quick Reference Manuals from Bogart Engineering for the SC-2030 Solar Charger and the TM-2030 Battery Monitor.



This is what TM-2030 programming changes I made so far:​

Important: Program in this order:

First; Change P-7 to "L-3" or "L-4" (highest level of options) (I chose L-4)
Second; Go to P-22 next to select your battery type (mine were 232AH Interstates so chose P-13)
Lastly, From information suggested by HandyBob and Kelly, I changed:
P-1 ("charged" setpoint voltage) to 14.6V
P-3 (battery capacity) to 200
P-10 (efficiency factor) to 97


Great resources:
Sprinter/Unity Forum
Kelly RV Solar Blog
HandyBob's Blog


If you have questions, ask Kelly. He's a wealth of information and willing to share it with you. Thanks again Kelly for all your help and supplying all the wonderful links!!!


"Gracie" Our 2015 Travel Leisure Van, Unity MB
'Gracie'.jpg

Jim Sagerser
Jim-&-Fish.jpg

A Cabin by the Pond in Alaska
 
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Tannys

2016 Unity TB
Nice job! Thank you for sharing your experience with a great presentation for visual learners.
 

lvuman

Active member
I set P-3 to 200 after some information I gleaned from HandyBob. He suggested the P-3 capacity setting be reduced by at least 10% from the factory claim of capacity to be more accurate. Ten percent less of 232 would be 208.8 however you must select settings in multiples of 10 so set it at 200. Could have set it at 210 also.
 

Klipstr

2018 Wonder FTB
Without trivializing the amount of work that lvuman did on his rig it should be noted that he went from not being sure how to do this to doing it in the period of about two weeks! My point is most of you can probably do this on your own! If you need help, ask here or contact me. I am happy to get you started. I'm trying to find a good alternative to the flex panels that will fit on the roof. AMSOLAR has 100W aluminum framed panels that look good but require a bit more installation than simply gluing down the flat panels. The install looks good but one would be drilling at least eight holes per panel to mount them. Or glue the mounts down...

Bottom line: solar on Unity is evolving because of all the work being done here! Jump on!
 

ablock

Member
AMSOLAR has 100W aluminum framed panels that look good but require a bit more installation than simply gluing down the flat panels. The install looks good but one would be drilling at least eight holes per panel to mount them. Or glue the mounts down...
Drilling holes is definitely not required. AM Solar recommends using the 3M VHB tape strips to attach their mounts. It's easy and takes about 5 minutes per panel.

You could also use something like Weld-Mount studs if you don't trust the VHB. But we've put about 1,300 miles on the van since installing the panels and had no problems (and AM Solar says they have not had any reports of separation AFAIK).
 

Danarbor

2017/2018 Unity Twin Bed
Thank you luvman for the amazing tutorial you put together documenting the installation of your four solar panels. You really did an outstanding job with the tutorial and I'm sure you invested a lot of your time doing so! Would you feel comfortable sharing how much you had in material costs to complete the project? I have a 2017/2018 UTB on order and since LTV now offers four 100w factory installed panels for $2,860 I was seriously considering checking that box. I'm guessing the material cost for your project were significantly less than $2,860 and being a Scot I'm always interested in saving money. Having said that I sometimes joke that my brother got all of the mechanical skills in the family and I got stuck with the good looks and charm.....well, at least my brother really does have incredible mechanical skills. In any event I'd be interested to know what your costs were to weigh whether or not I want to undertake the project myself or write the check. Thank you in advance for your response!
 

ablock

Member
@Danarbor, I obviously can't speak for luvman but can tell you the budget on our solar install. I did a full electrical (lithium + inverter) upgrade at the same time, so this would only be for the solar:

- (4) AM Solar SP100 panels with mounts and connection accessories: $1,280 (I paid a bit less because I preordered when these came out)
- (1) AM Solar combiner box with extra ports: $90
- (1) Victron BlueSolar MPPT 100/50 charge controller: $330
- (2) Blue Sea Series 285 panel-mount circuit breakers (30A input / 60A output): $82
- (1) Dicor self-leveling sealant: $11
- Miscellaneous connectors: $50

So about $1,850 total, not including shipping. But please note that you would need the LTV solar prewire for this to work (we already had the 200W of factory-installed solar, so this was an expansion not a fresh install). If LTV doesn't do the solar prewire you are running your own cable from the roof. In that case you would need to add the price of cable; figure 30' of 8 AWG red + black welding cable, about $50 shipped. The installation itself would be a pain though.

Hope that helps put it in perspective.
 

Danarbor

2017/2018 Unity Twin Bed
@Danarbor, I obviously can't speak for luvman but can tell you the budget on our solar install. I did a full electrical (lithium + inverter) upgrade at the same time, so this would only be for the solar:

- (4) AM Solar SP100 panels with mounts and connection accessories: $1,280 (I paid a bit less because I preordered when these came out)
- (1) AM Solar combiner box with extra ports: $90
- (1) Victron BlueSolar MPPT 100/50 charge controller: $330
- (2) Blue Sea Series 285 panel-mount circuit breakers (30A input / 60A output): $82
- (1) Dicor self-leveling sealant: $11
- Miscellaneous connectors: $50

So about $1,850 total, not including shipping. But please note that you would need the LTV solar prewire for this to work (we already had the 200W of factory-installed solar, so this was an expansion not a fresh install). If LTV doesn't do the solar prewire you are running your own cable from the roof. In that case you would need to add the price of cable; figure 30' of 8 AWG red + black welding cable, about $50 shipped. The installation itself would be a pain though.

Hope that helps put it in perspective.
Thank you very much for putting together the detailed breakdown on your costs to install your solar panels, ablock. Given that we're talking about a $1,000 difference (which admittedly is not insignificant) between the costs for materials vs. having LTV install the panels I think I'll be writing a check to have them install the panels. Thanks once again for the time you took to post the costs for your project.
 

lvuman

Active member
Thank you Danarbor for the kind words. Here's the cost breakdown of my install:

Four 100 watt solar panels $720
Eternabond tape $36
Pre-made 8AWG cables w/connectors $35
Combiner box $11
Buss bars for combiner box (Lowe’s) $8
6AWG wire from Lowe’s $15
2-wire thru-the-roof gland $24
Dicor sealant $8
Two 30 amp breakers $16
SC-2030 Solar Charger $119
Trimetric TM-2030 Battery Monitor $150
4-wire harness for battery monitor $13
House 4-wire phone cable $5
Battery box temp sensor $12
500 amp shunt $27
Short 2/0awg battery cable $9
10" 4awg welding cable $14
Misc shipping $50

Total: $1,272

Great system. It's worked flawlessly. Just took a 550 mile trip with speeds 65-80mph. Eternabond tape is working great and made the install easy! Note: For $200 more, I could have made it a 500 watt system. Just didn't have room for the 5th panel. Will relocate the satellite dish cable in the future to make room for the 5th panel.
 
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Danarbor

2017/2018 Unity Twin Bed
You are most welcome, lvuman; well-deserved praise for the outstanding tutorial you provided showing how to install solar panels on a LTV Unity. And thank you for taking the time, as ablock did, to share the costs for your project. I'm constantly amazed by how generous forum members are in taking the time to share their knowledge and experiences upgrading their RVs. There are some incredibly bright and talented members on this forum and I've learned a tremendous amount since I joined the forum in August of last year. So thanks once again for your considerable contributions! ?? ?
 

lvuman

Active member
Update: I repositioned the wires from the satellite installation to allow room by the ladder for the 5th, 100w panel. After the satellite cables were repositioned, the installation of the 5th panel took 70 minutes to complete which included wiring the new panel into the existing combiner box.

5th-Panel.jpg

This is the amp output at 11:45 with the battery at about 80% charged. I left a load on the system overnight to draw it down to see it charge the next day.

Monitor.jpg

BTW, the original eternabond tape looks and is doing great. The roof was very dusty when I started the 5th panel installation but after sweeping it off, the eternabond edges still looked clean and fresh. Love that stuff!
 

lvuman

Active member
Important update! The original 100W solar panels made by Suaoki failed with less than two years of service. About 6 months ago, the top protective layer delaminated and flaked off like flakes of snow. They still worked but looked hazy. A few months ago, they were hit by small hail about the size of a marble and quit working altogether. I wish they would have worked out as they were super simple to install with the Eternabond tape, laid flat, and weighed only about 5 lbs apiece. Oh well, time to move forward. After seeing several posts on the Renogy 100W Monocrystalline (slim design) Solar Panel I decided to remove my flex panels and install the rigid panels.

It was very easy to remove my existing panels as I only had to cut the Eternabond tape around the flex panels with a razor knife. I removed all 5 panels in 35 minutes. I cut the positive and negative leads as close to the old panels as possible to leave plenty of room to add new MC4 connectors.

I purchased 5 new Renogy 100W rigid panels and the mounting Z Brackets. The total cost, with a 10% discount, came to $598.40 with free shipping.

Renogy Order.jpg

I also ordered a pack of 5 MC4 male/female connectors made by Renogy for $9.99.

The panels appear to be of excellent quality and best of all, they have a (pro-rated) 25-year power output warranty.

The negative things to consider is the additional weight (about a + 10lbs increase per panel over the flex panels and not as aerodynamic.

They were also super easy to install. I installed the Z-brackets and set each panel on the roof to mark their locations. I applied a generous amount of Dicor on the area under each Z-bracket foot and then applied a generous amount on top of the brackets. I let them set several days and checked how well they adhered to the roof. I am completely confident they are securely attached without the need to put screws in the roof. This is a personal choice but I did pull on the end of several panels and determined it would be difficult to remove them without removing the Dicor first. I was able to install all panels in about 3 hours and then wired the new panels to the existing installation in about 2 hours a few days later.

This is the final installation:

New-Panels.jpg

Dicor-Mount.jpg


The empty boxes are useful in testing each panel and for keeping the panels from producing amps while completing the electrical connections. I removed and replace one cover at a time to test the individual panels to check for dead panels.

Covers.JPG

I tested the amp output on this date, November 2nd, in Chandler AZ, at 11:30 am. The sky was clear and the sun was fairly low on the horizon. I drew down the battery to 70% first and flipped the solar switch. It showed a positive charge of 17.4amps.

Amps.JPG
 
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Klipstr

2018 Wonder FTB
Nice update!

I like the mixture of the long skinny and fat wide Renogy panels. You squeezed all you could out the roof space. If you had been able to shoehorn one more in you could upgrade your charge controller to MPPT and really squeeze out the amps. But you can do that at any time (if you can get an even number of panels up there!). I have a feeling that in full sun straight above you will produce more than the 30A rated by your charge controller. Next June will tell!

I wish I had never heard of flat flexible solar panels. What a pain! At least you were able to get yours off the roof!

Did you contact Suaoki? I was able to get the original manufacturer or my panels to give me my money back! It was especially useful that I had purchased those panels on Amazon and could threaten to write a very negative review of the panels for them. I even wrote it and sent it to them without posting it. Got a full refund pretty quickly after that...


Prospective new Unity or Wonder buyers: Don't get the factory solar. Ask for the prewire and let's do this right!
 
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lvuman

Active member
I didn't ask for a refund because of the ultimate damage was caused by the hail but I'm ok what that and happy to have found the new panels.
 

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