DIY Solar Generator Series - Part 5

DIY Solar Generator – Plexiglass Cover and Improvements

In this update to our DIY Solar Generator how-to series, I am going to show you how to build an acrylic Plexiglass cover for the inside of the solar generator, so that we can store things like jumper cables inside the case without worry about shorting out or damaging any of our wiring connections. I will also show you some updates and improvements that I have made since the original videos, including a way to automatically disconnect the solar charger from the battery when the solar panels are unplugged. This will keep the solar charger from slowly running down the battery while in storage, without having to remember to turn on or off a disconnect switch. I will also show you a better solution I have found for the solar cable wire including heavier gauge cable, for less cost, and a built in cord wrap.

 

Plexiglass / Acrylic Cover

For the Plexiglass cover, if you have been following along with this build series, you can download the cut diagram below that I have made. It should work for you if you have mounted your components in the same positions I did. If not, you can create your own template using some cardboard. I will do another video to show you how to create cardboard templates.

Once you have your cut diagram, we can start cutting out the individual panels. The quickest and easiest way is to score the Plexiglass using either a Plexiglass knife, or a sharp utility knife. Once you have measured where you need to cut, use a straight edge to guide the knife and score the panel. Score it several times to help you get a clean break.

Then place the scored line along a sharp corner, and evenly flex the panel until it snaps along the score line. Use this same process for all of the panel in the cut diagram.

The two panels with an inside corner require a couple of extra steps. First we will drill a small hole at the inside corner. This is to keep the panel from breaking further than that point. When drilling Plexiglass, you will want to use the drill in reverse at high speed. The friction of the drill bit actually melts its way through, which keeps you from chipping and cracking the panel.

Then to assist the break in starting exactly where we want it, notch the two scored lines about an inch in from each end. You can use a vibrating multi-purpose saw like I am using here, or instead a fine tooth jigsaw or a Dremel type cutoff wheel.
At this point we will put the longest edge against our corner, and gently flex the panel until both scored edges break clean.

After you have all the panels cut, we will assemble them using acrylic solvent cement. I will use a water-thin fast set solvent (#4) initially, and then follow that up later with a thicker #16 cement to strengthen the joints. You can find links to where I purchased both of these in the description and in my linked blog post. I also purchased both of the applicators I used from Amazon as well. I will post those links below as well.

Acrylic-Solvent-Cement

Lay the pieces on cardboard to soak up any excess solvent as you work. The solvent has a set time of about two minutes, so once applied you can make small adjustments. The joint will not reach full strength for 24 hours, so even after it is set, you still need to be careful at first.

Keep adding panels, referencing the cut diagram for their placement. You can use the existing panels you have already glued as alignment guides, so that everything matches together nicely.
After you have all the panels together, let it rest for several hours to gain strength. Then use the #16 solvent, which is much thicker, to strengthen the corners and fill any small gaps.

Improvements to Solar Cable and Connector

Previously I had recommended using high quality heavy gauge speaker wire for the solar cable, because it came with two wires bundled together, and was much less expensive than the photo-voltaic wire, which is not very flexible for coiling long lengths. Since then I discovered that you can purchase outdoor rated extension cords with 12-gauge wire for even less than the speaker wire, and not only is it more durable and weather resistant, the wire is much more flexible and great for coiling longer lengths.

Solar Panel Cable & Connector

You will want to snip both ends of your cord, and then carefully use a sharp knife to remove the outer insulation sheath. You can also trim off the green ground wire since we only need two conductors.

We need to connect these to the MC solar panel connector pigtails on the solar panel side. Make sure to connect the MC connector pigtails included with our solar kit to the solar panel, and make sure the solar panel wire with the negative (-) label is connected to our black wire in the extension cord. The white extension cord wire will be connected to the solar panel wire that is labeled positive with the plus (+) sign.

Then wrap the end of the extension cable with some electric tape for additional strain relief. I used heat shrink butt splices here for the wires, but if you did not, you could also wrap them too for weather proofing as well.

On the solar generator end of the extension cord, we will connect our 6 pin trailer plug, just like before. The black ground wire will go to the pin connector labeled as ground. Our white positive wire will connect to the center pin. We will be adding an additional jumper wire as well. This is part of the solution I talked about for having an automatic disconnect for the solar charge controller. You will want to use at least 14 AWG wire, and we will connect it to the pins labeled for the L and R turn signal. After that, we can then assemble the trailer plug and tighten the wire clamp. The extension cord wire also works very nicely with the 6 pin trailer plug. This makes for a really rugged connector.

I also added an inexpensive cord wrap for coiling up the solar panel cable for storage and when we don’t need the full length. I also purchased this from Amazon and the link will be in the video description and blog post. After coiling up the cable, I position it where I want to be mounted on the back of the panel, and used some construction adhesive to glue it into place.

Automatic Disconnect for Solar Charge Controller

The last improvement and modification I made was to add the auto disconnect switch for our solar controller. Originally, I didn’t feel the solar generator should require one, because the solar charge controllers are designed to be connected to the battery 24/7, so I assumed the battery draw should be very minimal when there is no sun light, much like the clock in your car should not run the battery down when your car is parked for a long time.

Automatic Solar Panel Charge Controller Disconnect

I decided to measure the current draw from the solar controller when the panels were disconnected. The idle current draw measured at 8 milliamps. While that would still take several weeks to drain the battery, it is more draw than I had expected. I didn’t want to add a manual disconnect switch, because I didn’t want to have to worry about forgetting to turn the charge controller on or off all the time. I came up with a better solution that I am really happy with. We are using a 6 pin trailer connector for our solar panels because they are weather proof, rugged, and very inexpensive. But we are only actually using 2 of the 6 pins. So we can use 2 more of the pins as an integrated disconnect switch.

Earlier in the video we already put a jumper wire across two of the pins in the male plug. Now we just need to find the wire inside our solar generator that runs between our fuse block, and the solar charge controller. Snip that wire, and then splice in a longer wire extensions to each end the wire you just cut. We will be routing these extension wires to the female side of our 6 pin trailer connector. It helps to neaten up the wires before we trim them to so that we can determine the proper length. It is also easier to connect the new wires to their pins if you remove the trailer connector from the case.

Thread the new wires first through the protective cover, and then through the hole in the Pelican case. Then determine the length needed where to trim and strip the ends of the wires. Connect the two wires to the L and R turn signal pins, like before. It does not matter which one goes where, because our jumper wire will short them together, turning on the solar controller, whenever we plug in the solar panels. When we unplug the solar panels, the solar charger is automatically disconnected from the battery.

Future Updates

I will be building some portable quick connect battery bank expander units in the next video in this series. The design will allow for connecting multiple ones in a daisy chain using the 350 Amp Quick Disconnect Port. I will also show you how to add multiple panels. The current design of our solar generator will allow up to four 100 Watt panels to be connected.

Let me know in the comments if you have any additional ideas you would like to see as well.

Downloads

Acrylic Cover Cut Diagram – Cut sheet with dimensions and assembly information for the protective acrylic cover for our 2000W Solar Generator.

Main Components for the Solar Generator

Additional Components & Supplies

To see the full list of components used in this build, see Part 1 – How to Build a Large solar Generator

39 thoughts on “DIY Solar Generator – Plexiglass Cover and Improvements”

    1. I found the best prices on acrylic sheets at a local Rural King. They only had it in one thickness, which I think was approx. 1/8″ but it worked pretty well. If you are using the same design I did, you may need to adjust some of the cut dimensions for thicker acrylic panels.

  1. Excellent video series! Looking forward to seeing your update covering battery and panel expansion. This looks much better than plunking money down for a premade. Thanks!

  2. Hi Mark : fabulous series. Looking forward to hearing how its performing as well as the next installment about expansion.

    Question : (apologies if it was already covered), I was wondering what the decision process was with the Solar Controller that came with the panels. I see that its a PWM controller versus the more expensive MPPT controllers. Can you describe why one might work better than another in this type of setup ?

    My ideal use of this type of generator would be in place of a standard RV gas or propane generator for running normal AC stuff like Laptops, blenders, recharging electronics, etc. while “dry camping” or boondocking.

    thanks again !

    1. Hi Pablo, Good question on PWM vs MPTT. Went with PWM because it was included in the solar panel kit I used. MPTT are generally a little more efficient due to how they operate, but also more expensive. May try to do a follow up post in the future that gets into the differences in how they work.

  3. How hot does the inverter and other electronics in the Pelican case get while charging or under heavy load? Should venting the case be considered?

    1. In my usage, heat has not been an issue. You can open the case to add ventilation if needed, but you will lose weather resistance. The conditions you use the generator may be different than mine. High load in a dry dessert vs windy /rainy days, etc.

  4. Great series. I have been wanting to build a solar generator for years. I didnt think I understood enough about it until I saw your videos. Question… can you add another volt meter to see how much voltage is coming in from the pannels? And maybe another volt meter to see how much energy is being used?

    1. Thanks Richard! You could add a voltage gauge to see the panel voltage, but when the panel voltage is high enough to be used for charging the battery the PWM controller should cause the panel voltage to nearly match the battery voltage as it is charging. To monitor power being used, you would want a current / amperage gauge. You can also get combination voltage/current gauges that will calculate the current wattage as well.

  5. Just ordered all of my parts. Really looking forward to the next installment on the expansion of the system. I have been doing a lot of research on the ready made kits out there. I have to say, your design puts all the others to shame. The well thought out extras places this one at the top of my list and less than half the cost. Looking forward to getting it all together and taking it down to my camp with me this summer! Thanks again Mark.

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  6. Great videos, thank you. Your Amazon link to the Krieger inverter goes to a page with multiple choices of sizes, none of which is a 2000. Should we bump up to the 3000 size? Thanks again
    Bob

    1. Hi Bob, Thanks for letting me know! Hmm, I am not sure if they are temporarily not listing the 2kw unit anymore, or if they will be no longer selling it. The 3kw will wire up the same, but it looks like it is a taller design, so you may need to make some adjustments for how it mounts. If you try it, please let me know how it goes!

  7. To Robert M:

    If you’re making your own power generator based on this series, where Mark puts the battery is really the best place to put it in that Pelican case. I’d go with the 1500 watt model https://www.amazon.com/KRI%C3%8BGER-KR1500-Inverter-Outlets-Installation/dp/B00DNL05GW as its the same thickness as the 2000 model. Or you could decide to move the inverter to another location in the case, maybe even turn the battery 90 degrees (not sure how that would affect things when wheeling the case along).

    I’m making my own based on this series, but I’m using a 100AH battery which gives me only 1 or 2 mm of space between the battery and the Krieger 2000 watt inverter. My battery weighs about 65 pounds so I want it as close to the wheels as possible to minimize stress on the pull-up handle when wheeling the case around.

  8. Hi Mark and thank you for the great video guides. As a very novice electrician, I just finished building your 100W solar generator with the 3000W inverter and all of the listed wiring and switch improvements. The charge controller PV and Battery lights worked properly, before they were installed into the Pelican. Most everything now works as expected and on a sunny day I am getting 20V output from the trailer plug end of the solar panel.

    My concern goes to the finished hookup for the solar charge controller. As a trial, I plugged in two hand-tool battery chargers, drawing down my battery from 12.8 volts to 11.8 volts, with the PV panel plugged in. The charge controller now does not display that the battery is being charged by the solar panel; i.e., the green PV light on the controller shows a solid green and is not blinking slowly, as it should when the battery is being charged by the PV panel.

    Since the trailer plug now contains the LTS-RTS wires and jumper going to the battery wire on the charge controller, would this cause the charging light on the controller to maintain a solid green light for both the PV and Battery light displays? In other words, when using the Optima battery and with the PV panel hooked up, should there be three solid green lights displayed at all time? Thanks for your answer and for your great instruction.

  9. Hi Mark..
    Thank you for posting an awesome tutorial for making these generators..
    Please i will like to build a 4000 w system and i will like you to help me by telling me what type of components that i will need to build it .

    Best Regards,
    Daniel .

  10. Hi Mark, I too am interested in building a 4000w system. Have you done one yet, any advice or info? Going larger always changes some things and I would love your input on the following please. I was thinking of using the Krieger 4000w inverter, (2) VMAXSLR155AGM batteries, one in the case and one used for expansion. I was also interested in using a voltmeter that would display more system information such as total wats being used, voltage output, drain on system. With that in mind I was thinking about either the Baylite DC6.5-100v 0-100amp lcd or the Mictunning equivalent. Do you think that would work for what I am looking for, have you used either or do you have another one I should look into? Of course this would replace the Zowaysoon voltmeter you originally listed. Also if I do decide not to use the Zowaysoon voltmeter then I will need to buy an individual car cigarette charge port and USB charge ports. Do you have specific brands I should look at for those? Also I was unable to locate the type of toggle switches you used on your amazon parts list. Being that I will be using a larger battery the 155amp hour VMAX one in the case and one in an expansion case would you still use the Schumacher 1.5 smart charger or would you use something else and what? I was curious if I should look into a VMAX smart charger for a solar system and if I should get a larger charging amp so if I charge using the grid it charges somewhat faster…thoughts? Final question is with the pelican 1620 case being this build is larger was curious if you would use the same case or different? Again Mark thank you so much for all of your videos and directions and time you put into all this and helping others like me, we greatly appreciate your time and expertise and experience.

  11. HEADS UP FOLKS! I’ve now had my system in place for about a year and a serious flaw has developed. My Renogy Wanderer Solar Controller started to act funny and finally quit working altogether. I figured it was a defective controller. Turns out it was not. It drove me crazy trying to find the problem, so I started checking all my wiring. The problem was in the trailer plug wiring – specifically the “jumper” wire set-up that created an automatic cut-off when to plug was disconnected. When I got to that wiring I noticed that the wire had seriously corroded, the coating had scorched and even the plastic housing of the plug had melted. Apparently, due to the closeness of the wiring connections and the need to use smaller gauge wire to avoid cross-contact, a “jump” between the terminals was happening even though no wires were touching. This created a small but continuous short in the battery (somewhat like running a light filament) and finally corroded the jumper wire enough to cause a complete disconnect when the trailer plug was plugged in. I eliminated the jumper wire and went back to the original wiring plan and it works fine other than it ruined a very expensive battery.

    Possible fix suggestion: Use a different connector system off the solar panels. You need to use a plug that will handle a lot heaver gauge wire as well as having larger spacing between connections. There’s really no need for anything more than a four prong plug so you should be able to find something a bit stouter.

    1. Hi Richard, that is strange one, thanks for letting us know! So far I haven’t experienced this issue with mine, and I am a bit surprised. I couldn’t find a current rating for the connector from the manufacture I used, but I have seen the same 6-pin trailer connector from other manufactures rate them at 40 amps continuous. Since even with 4 panels connected the charge controller can only output 30 amps, we should be ok on current capacity. Did you use the same gauge wire for the jumper as you did for the rest of the charge controller wiring?

      If you rather not wire in the jumper, that’s ok as well. Just be aware that if you have the unit in storage without the solar panels connected, the solar controller will slowly drain the battery down. You could pull the charge controller fuse when in storage to prevent this though!

  12. Mark, your amazing tutorial was so inspiring that I took it on as a summer project with my boys, in preparation for hurricane season here in Florida. With no previous electrical experience, with a lot of determination, a little frustration (crimping? an art form if you’ve never done it before), and tons of fun, we’ve almost competed our build. It’s so exciting to be this close… a couple of questions, if anyone can help:
    1) the GFCI outlet won’t work. We rechecked & redid our wiring to the outlet and inverter 3 times to be sure, but no green light and no current in it. It flashes a series of red lights. All other components are working fine though.
    2) My solar panel pigtails were not marked positive & negative. Is it safe to guess and take a chance? And how can I know if my panel is charging the battery? The voltmeter shows 12.6 even though the panel isn’t hooked up yet.
    3) Has anyone else fried a battery ,like what happened to Richard? (That must have been a disappointing experience, thanks for sharing Richard. I may opt for the original wiring too!)

    Thanks again for your generous spirit, Mark, sharing your knowlege with the world. You’re a great teacher and motivator. I’d be proud to boast your sticker on my generator when I share my build pics with the friends and neighbors who are humoring me with “good luck with that”, (lol)

    1. It’s a fun build, isn’t it? Once you’re done I’m sure you’ll appreciate having backup power available.

      *The GFCI outlet could be defective or, as simple as this sounds, it might need to be reset using the front buttons. Be sure your polarity is correct – the positive wire to the brass colored screws, the negative wire to the silver colored screws.

      *Check the wires coming from the panels. Look for one that has a small “rib” running down the outside. If it does, that’s positive. Also, sometimes the wires will have a “tracer” or colored (sometimes white) string inside one of the wires and not the other. The “tracer” wire is positive. And finally, if you have a silver wire in one side and a brass colored one in the other, the brass colored one is positive.

      *12.6 volts is the correct voltage for a fully charged battery.

      Just for chuckles, I checked with Amazon about a warranty replacement for the battery and they sent me one, no charge – how nice!

    2. Thanks Serina! I’m glad that you and your boys are enjoying the build!

      I agree with everything Richard said below. Another simple test for the inverter wiring is see if the built-in outlets on the inverter work. If so, then you know your problem lies with either the wiring to the GFCI or the GFCI itself. I am starting to think the GFCI outlets may not be necessary. I have read both ways on whether they add any additional protection when used with an inverter. I need to research that more, and I had used the GFCI because I wanted to error on the side of caution.

      I do not know if wiring the solar panels backwards to the charge controller will damage it or not. It may have reverse polarity protection, but I haven’t tested that! If you have a volt meter, that is a simple way to verify the wire polarities from the panels. Another way would be to use one of the LED work lamps (disconnected from the generator). LED lamps will only light if wired correctly, but usually won’t hurt anything if wired in reverse.

  13. Awesome, thanks guys! I’ll get back to you on what I find out. This is really fun and quite the learning curve. Keep you posted… 🙂

  14. Hey Mark, Richard and Serina…i was just thinking about the solar charge controller and the jumper wire….instead couldn’t you just wire up another on/off switch to the charge controller and when using solar charging switch must be on, when in storage switch off to save battery.

    1. Hi AL, yes that would work as well! The jumper wire is acting exactly like a switch built into the solar panel input connector. I liked that because you didn’t need to remember to connect / disconnect the solar charge controller. It was automatic.

    2. Al, I decided to go back to the auto shut off wiring that Mark proposed in the updates but I used electrical tape to insulate each wire. Time will tell if my battery meets the same fate as Richard’s first battery, but my fingers are crossed. It drove me nuts to close the case while knowing the controller’s green light was still on. Silly detail but very gratifying to know it was off when not in use.

      No GFCI worked… tried 3 but decided to not bother with one after an electrician I met in the Home Depot aisle told me the inverter already has a circuit interrupter and therefore none on the shelves would work. Now I use it as a pass – through which is super convenient.

      This was the most fun project and learning curve I’ve had in a long time. Now onto battery expansion! Thanks, Mark!

  15. Hi Mark, I just got all of my components to build a solar generator. I wanted to get your opinion before I proceed. I will be using two 100watt Renergy panels, and I opted for a better solar charger the Renergy 40AMP MPPT, and the battery is a VMAX extreme 155amp hour, and a battery expansion like you have with a VMAX extreme 135amp hour. My question is still with the 6pin round trailer plug, the outdoor extension cord and the quick connect tow plug. I just found out that the 6pin round plug is rated for 40amps max, but the outdoor extension cord is rated at 15 amps and I have no idea (yet) what the quick connect tow plug is rated. Should I buy a heavier rated plug and connector and wire that is all rated >40amps? I am just very new to all this and I do want to use the jumper wire as well as it’s just easier than a switch and I also want to be EXTREEMLY careful not to fry or short any of this equipment as I have now invested a decent amount of money into this project. Thanks again for your time and thoughts.

    1. Hi Al, The 100 watt panels in perfect conditions / direct sunlight will provide 100 watts each, which works out to about 8.3 amps in a 12 volt system. So with 2 panels, you should have a max current of 17 amps. When you say quick connect tow plug, I assume you mean the other side of the 6 pin round trailer plug? So far I have always seen these style plugs max current rating 40 amps, so you should be ok there. Make sure your connections are tight though, as poor connections can cause heat. It wouldn’t be a bad idea to feel the wires / plug connectors to double check for excess heat when the unit is charging in sunny conditions. If you used the 12 AWG outdoor power cord I linked, you should be ok there as well. 12 AWG is good for 20-30 amps according to this chart: https://en.wikipedia.org/wiki/American_wire_gauge
      The cord manufactures list the 15 amps rating for household 120v AC use since that is all that style receptacle is rated for. 20 amp circuits have a rotated prong on their plug. You can go larger of course, but wire gets pretty expensive and bulky at that point, however you would get better efficiency due to the less voltage drop.

  16. Thank you Mark. You are a rockstar for taking the time to answer questions and help teach and pass on your knowledge. It is truly appreciated. Yes I am using everything you linked to Amazon with the exception of a few items. Once I am finished with my build I will post photos og the finished project if this forum allows it. Again many many thanks Mark.

    Regards
    Al

  17. Ha! The Krieger 3000 booklet states it is not compatible with most GFCI outoets and is not made to be wired to one. So, if you’ve been pulling out your hair trying to rewire over and over, stop, breathe and return the outlet. Your wiring technique isn’t in question, the inverter has a shut off and/or interrupter and/or alarm for malfunctions.

  18. All done, works like a charm and my fridge runs perfectly. Got my cool stickers on it and have passed on the link to everyone I know so they can check it out. If I can do this, anyone can, because the tutorials are awesome and so clear.
    My tactic was to watch the whole series, including updates several times, take notes on the written tutorial so that I could switch to the updates when needed. So you might need to switch to the updates a couple of times during your build, but it’s worth it and ultimately will save time.
    Renogy has incredible customer support if you have questions about alarms, etc.
    Mark, thanks for your genius and generosity for sharing this!

    1. Thanks for the update and kind words Serina! So glad you are liking the generator, and thanks so much for sharing the link to your friends!!

    2. Serina could you post the link for us all to view or could you send me the link. I am in the middle of my build and I would love to take a look at what you accomplished. I will post my photos and final product once complete as well. It’s taking me some time as I have a five year old, three year old and a two month old needing most of my time….lol…..thanks in advance.

  19. Hi Mark,
    I watch one of your Video on how to build a Portable Solar Generator }3000 Watts]
    I was amazed, your work is very good and I want to do the same.
    My question is, can this 3,000 watts Portable Solar Generator carry the loads of appliances like
    1. Big Deep frizzier.
    2. Big Photo copy machine like RICOH AFICIO MP 2000.
    3. Big Printer like HP LaserJet 2840.
    4. Plumbing Machine.
    Otherwise can you build 8,000 watts Portable Solar Generator?
    I used numbers 1-3 in my Computer Centre with petrol Generator, I am tired of using petrol generator because of its loud sound.
    Where in Nigeria I can get your Agent to buy this Portable Solar Generator?
    Please, I need your reply.

    Thanks very much.
    ADEJINMI SAMUEL O.
    08066493479 ]SMS ONLY]

    1. Adejimni, the portable unit Mark designed is really intended (I believe ) for shorter uses or temporary use. If you want a permanent off-grid solution to run the devices you listed, you will need a lot more power and more batteries to store it. Renogy has a lot of info online and they can help you figure out what you need. See http://www.renogy.com and speak to experts before you invest, to maximize your budget and get it right from the start.

      Also, in th US we don’t use agents. This tutorial is meant to teach you to build it yourself so you might need to get comparable items from Europe or use a customs broker to get them shipped to you.

      So forum friends, yes, my fridge worked but only for 1 hour. It draws more amperage (15 amps) per hour than 1 panel can charge and my battery has ony 55 AH. The solution is to get a 12 volt fridge like the kind truckers use or you’d get in an RV, camper or boat. Then this unit would serve as sufficient in an emergency back up situation as is.

      A
      You could take it a step further. If you’re looking to use this for household items as opposed to tools in the field or a winch, for example, you might consider getting a battery with more AH and that is designed for solar. Renogy has several options as do other companies. I’m eventually going to switch to a higher amp hour AGM battery & keep the Optima bluetop for my portable battery expansion box, for road trips and overlanding day trips.

      Al, I don’t know how to upload pics, sorry. Mine looks almost like Mark’s except my “outlet” is a pass-through. The Krieger 3000 doesn’t accept GFCI because one is built in.

      Sticker looks good on it! I still get impressed every time I look at it. Happy rays, y’all!

  20. I have a question: would this have the capacity to run my household fridge during a power outage? Not continuously mind, but for an hour here and there to keep things cold.

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