Renogy 100W folding solar suitcase

PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
I always wanted to build something like this on my own and piece together choice materials, but never seemed to get around to it.

So I picked up a 100 watt pre-built portable from Renogy:
http://www.renogy-store.com/100W-Suitcase-p/kit-stcs100d.htm

Essentially it is two 50 watt panels in parallel with hinges, with a pwm charge controller, mc4 cabling, angle stands, handle, cordura soft-case, etc. There is a smaller 60 watt version available too. Cabling is ok, and uses a 50A Anderson connector between the battery clamps and the main 15 foot cabling. So if you want a custom cable without cutting the existing wiring, you just need to get your hands on the anderson connectors to make up something else. Nice to see a 7.5A mini-fuse inline. Kind of wish they would have included a spare, but I'll hunt a spare down to have on hand.

When measured with my own ammeters and voltmeters, it seems to meet specs. One thing I like about Renogy is that you don't have to hunt for the specs on anything. It met specs of about 5.7A during bulk, and even saw 8A on a few edge-of-cloud incidents.

Build quality is generally good. Nope, not as good as my Sharp panels, but good enough and better than expected.

The pwm charge controller is mounted on a plate under one of the panels that can swing out. The plate itself is attached to the underside of the panel with velcro. This makes it easier to swing out and replace with a controller of your own choosing should you want to change it out. Initially, mine was so covered with velcro, and pushed in so hard, that I thought I was going to break the panel. Obviously, no leveraging force should be used, so I just pulled slowly and steadily to get it loose. When storing, I don't push the plate back down very hard, to make pulling the velcro apart for swingouts a LOT easier.

The main reason you might want to swing the plate out that holds the controller, is that when you pull out the angle-legs, it is nearly impossible to operate the controller tucked up so far behind the panel, unless you want to use a vehicle-creeper. :) When you pull the plate apart from the velcro, the controller can now hang vertically and is much easier to operate.

The second main reason is that the included controller, and EPsolar Viewstar, has ambient temperature compensation. I found that if I left it velcro'd to the back of the panel, the temp-comp was innacurate due to being so close to the heat on the back of the panel. By loosening the velcro hold, and letting it hang vertically, temp comp was much more accurate, and provided better cooling to the CC.

Ok, for most of us, the EPsolar Viewstar is on the very budget side of CC's. Yet I will give it this, that the capabilities it has for monitoring, load / light control, and the ability to custom set voltages for bulk/absorb/float, and even EQ along with changing the temp-comp rate too. It states that it will do EQ every 28 days, but I suppose if you don't want that, you can set the EQ voltage to the absorb voltage to negate that feature. And I'm not sure if merely pulling the battery leads will reset that, so in a portable application of less than a month, it may not kick in at all. Note that in the manual, they use the term "boost" for what we know as "absorb".

The EPsolar also has timeouts for boost/absorb, rather than measuring end-amps, so that may not be suitable for your situation. One possible work-around that I do is merely set my float voltage the same as the boost/absorb voltage with this CC. My plan is to put my Morningstar or Xantrex controllers in there, but so far, the EPsolar CC isn't giving me any trouble.

If I were taking this thing into the field, I'd make darn sure I had a backup charge controller, or obviously just use one that you prefer instead. The swinging plate makes it easy to mount your own.

Behind each panel's junction box appears to be a single schottky bypass diode - I think. While the system worked out of the box, I took the liberty of resoldering the wire connections in the junction box, and clean up a few "frog hairs" from around the charge controller connectors. It wasn't bad, but I wanted to make sure all connections were absolutely solid. I keep it stored in the case with a towel, not only to keep the panels clean, but to cover them as well during initial setup. This means placing the towel over the panels, attaching the clamps to the batteries, and the whipping the towel off the panels matador style for a little flair. :)

So far I'm pretty happy with it. Still, hard core portable users may think twice about carrying around glass panels, and opt for something like a flexible panel setup instead. I have had every intention of putting together something like this myself with higher quality components, but as a professional procrastinator, I bit the bullet and went pre-assembled.

Comments

  • AuricTechAuricTech Solar Expert Posts: 140 ✭✭
    Re: Renogy 100W folding solar suitcase

    What gauge wire does it use to connect the CC to the battery? I'm guessing 10 AWG, but I didn't see anything at the link you included.
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Renogy 100W folding solar suitcase

    It looks to be about #10 gauge.

    But, maybe because they ran out of wire, my black/negative lead seems a bit smaller, like 12 or 14 gauge! Still, that handles 5.5A fine at such a short run. I thought that was a bit weird though having two different gauges on the clamps.

    I'm really glad you had me look - they were a bit stingy with the solder on my positive terminal clamp, so I'm going in with my big iron to touch up.

    You bring up a good point for newcomers to the scene though - you want to run the shortest possible length of cabling between your controller and the battery. A long extension between the two can result in a big voltage drop for a nominal 12v system by the time it reaches the battery, so keep it short.
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Renogy 100W folding solar suitcase

    Can you say voltage drop? Fix is simple however.

    I finally got around to looking at the wires closely after a frustrating day of the batteries not coming up to my programmed voltages - great conditions, pumping 5.7A as spec'd, middle of solar-insolation, good angles, etc.

    The wires are 1.5mm sq, which roughly translates into about 15 AWG. Running the calcs here show why I had to purposely set my voltages about .4v higher than normal. 14.4v desired at 5.7A with 15 foot one way trip through #14 AWG (I'll be generous here):

    http://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=8.286&voltage=14.7&phase=dc&noofconductor=1&distance=15&distanceunit=feet&amperes=5.7&x=60&y=14

    Tada! Now it plays nicely when I know how much to compensate. I turned off the temp-comp temporarily to make sure it wasn't part of the problem, and re-enabled it later when I was satisfied.

    So there you go. Got stumped by a long run of thin cable between controller and battery. While I would like to make up a set of #8 or #10 AWG minimum, for weight savings, I'll probably just have to remember that if I want 14.4v, to compensate for voltage drop by setting it to 14.8 in the controller. I never run more than 2-3 feet from my controller to battery in my other setups, and smacked my head when it dawned on me. :)

    I notice that they sell lengths of "tray cables" that are already at least 12 gauge or better, so I'm a little surprised at the #15 / 1.5mmSq equivalent here. Probably to save weight for portability. Heh, just be sure to compensate for it!

    Problem: even though this compensation is a good idea at the start of boost/absorb, when currents are very low near the end of absorb, the discrepency is much smaller, and if you are a stickler about voltages, this might put you over voltage / small current.

    Argh. The REAL solution is to just use larger cable. Maybe I'll just split the difference and set my controller .2v higher than normal and live with it until I get larger cabling.
  • BB.BB. Super Moderators, Administrators Posts: 30,058 admin
    Re: Renogy 100W folding solar suitcase

    Ideally, I would be recommending around 0.05 to 0.10 volt maximum drop from controller to 12 volt battery bank.

    Having extra resistance between the controller and the battery bank just confuses the charge controller, slows down charging, and makes the set points all wrong.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490mike95490 Solar Expert Posts: 8,614 ✭✭✭✭✭
    Re: Renogy 100W folding solar suitcase
    I'll probably just have to remember that if I want 14.4v, to compensate for voltage drop by setting it to 14.8 in the controller.

    Noooo !

    This will be fine when you are pumping a lot of amps in, and have the voltage drop. BUT, as the battery charges up and the amps decrease, the voltage drop decreases too, and you WILL end up floating your battery very close to 14.8v
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

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  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Renogy 100W folding solar suitcase

    Yep - pretty sure I'll be making my own cable to keep the losses lower. I wonder how many others out there are really running insufficient cabling from their controller to their batteries without taking the time to measure or calculate it? Probably the easiest "upgrade" one could make to their 12v system.

    In this case, the net affect was like turning a 3-stage charging algorithm into a two-stage. It took much longer than normal to just get to the start of absorb, and such a long time to get to the absorb set point, that the controller switched to float automatically after 2 hours regardless. The higher than normal current in float was the first flag that signalled me that something was up.

    So BB and Mike - great advice! Since my controllers are normally very near the batteries, I never really looked at this issue with a hands-on situation. Wow.

    I suppose for some portable users, not doing a healthy absorb all the time may not be necessary, but for a geek like me with agm's that actually love absorb, (my portable is 55ah Optima blue-top) this became an issue.
  • jimindenverjimindenver Solar Expert Posts: 59 ✭✭
    Re: Renogy 100W folding solar suitcase

    I think the little portable set ups are great for a low power user or someone that wants to get their feet wet without spending a fortune or having a degree in solar. I started seeing them right after I finished my own portable and I have to say the 160w kit looked a lot easier to handle and store than my 230w panel was. I'm sure they are not of the highest quality but you get a lot more than some big name green company that is selling you more feel good eco advertizing than output.
  • PNjunctionPNjunction Solar Expert Posts: 762 ✭✭✭
    Re: Renogy 100W folding solar suitcase

    They are certainly attractive especially if your mechanical skills like mine are on the somewhat shoddy side. :)

    The Renogy meets spec, and has enough quality for what it is - a temporary portable system. The only thing a newcomer would have to watch out for is thinking that putting the controller close to the panels, rather than close to the battery is the right way to do it. The portable system only reverses convention out of necessity.

    However, that does not mean you have to live with it like that. You can remove the controller from the plate, and run your own wiring from the panels and place the controller near the battery should you choose.
  • scrubjaysnestscrubjaysnest Solar Expert Posts: 175 ✭✭✭
    Re: Renogy 100W folding solar suitcase

    My set up is a hybrid portable and I sure would like to find something like that solar suit case of theirs. Right now the panels 24X36 inch 80 watt, lay on the couch in the RV. Carry one panel down the steps at a time and hope you don't trip is the current method. Been thinking about adding a carrying handle to the panel. The stands are 3/4 inch pvc. Wiring to the cc is 10 awg marine grade with an up grade to 8 awg in progress.
  • AuricTechAuricTech Solar Expert Posts: 140 ✭✭
    Re: Renogy 100W folding solar suitcase

    BTW, in addition to the version that comes with a charge controller, Renogy also offers a 100W solar suitcase without charge controller, for $25 less than the CC version. It's one of two options I'm considering (the other is the Renogy 100W bendable panel) to charge the Yeti 400* I purchased with my REI 20%-off coupon code a couple of weeks ago. While the solar suitcase offers compactness when folded and has an integral support stand, it does so at the expense of being nearly 10x as heavy. Decisions, decisions...

    *I've already ordered Goal Zero's MC4-to-8mm adapter.
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