Angle of the dangle

oldmakooldmako Posts: 14Registered Users ✭✭
edited October 2017 in Solar Beginners Corner #1
Greetings again from uber noobie and neophyte wannabe.

Installing a 100 W  (26"X40") panel on the T-Top on my boat.  I will ONLY use this to keep my two deep cycle group 31 batts topped off and nothing more.   

Q.  IF I just mount it flat (easy install and ideal for when boat is in use - choppy water etc) will I get reasonable performance from this panel, or is this a complete bust? 

1.  The boat is on its trailer 85 percent of the time.  I'm lucky to get 8 days per month in summer, half that in spring and fall.   Maybe 2-3 to zero in winter when / if the humpbacks show up.

2.  Due to my parking spot, and the fact that the boat is tilted slightly bow up while on the trailer, my panel will likely tilt be a few degrees away from horizontal, and angled AWAY from the sun.  The bow of the boat is pointed south.

3.  According to the solar calculator I used  (, the following degrees of tilt are recommended.   

Winter - 30
Spring / Fall - 53
Summer - 76

Since I am not powering any appliances I don't require maximum performance from the panel.  But, since I am going through the trouble I am kicking around a pivoting mount that will allow me to change the inclination of the panel, IF required to get the voltage I need to maintain my batteries.   I figure that it would be fairly simple to design an articulating 3 position mount -

1- Stowed flat and secured for when the boat is in use.
2. A summer setting.
3. A second setting for Fall - Winter - Spring.  I'd just split the difference between 30 and 53 degrees.

Since the boat clangs and bangs when in use, I'm trying to come up with a mount that is both secure, yet somewhat giving and flexible to minimize the shock to the panel.  Its covered with tempered glass and has thin aluminum channel for its 4 rails.

I guess the Q is, will this panel perform adequately when relatively flat, or do I NEED to make a proper mount to get all perpendicular and what not??

Clueless in Virginia Beach.


  • EstragonEstragon Posts: 2,620Registered Users ✭✭✭✭
    You might want to check out

    It lets you put in various panel angles for your location to get a sense of what to expect.   Generally, having the panel flat isn't too bad in the spring/summer in higher latitudes.  What you lose in peak production is offset to some extent by extended morning/evening production. 

    Late fall and winter can be a problem though.  The weak sun and low sun angle will cut potential quite a bit.  Also, if the boat is near trees that shed leaves, a leaf or two sitting on the panel can cut output to near nothing (possibly less that zero), as will snow if that's a factor in your area.  If these factors might be an issue for you, maybe consider rigging up a way of hanging the panel vertically over the winter, and put it on the t-top for other seasons? 

    If your weather is cool over the winter, you may be better off disconnecting the batteries if you can't rig up a winter mount.  Battery self-discharge diminishes with lower temps, so leaving them for 3-4 months may be better than risking shaded panels and controller tare losses draining the batteries instead of floating them.
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • mcgivormcgivor Posts: 2,063Solar Expert ✭✭✭✭
    The idea of a pivot is a good idea, a hinge on the bow end, latch at stern end with a drop down leg, to give some angle. Another idea which jostling popped to mind is using casement window hinges would have to be weather/salt resistant, just an idea.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • oldmakooldmako Posts: 14Registered Users ✭✭
    edited October 2017 #4
    There will be pine needles, but only a few, from one tree.  With the panel is inclined 45 degrees I don't think that they'll be an issue for me.  Snow is a rarity here, although it has snowed more in the last 3 years then it has in the previous 25.  I will be surprised if the unit is ineffective during winter, provided I can keep it clean.  If so, I'll disconnect and or give them an occasional AC recharge.   

    Casement hinges.  Genius!  And, they're available in stainless.  Perfect.  Thanks.
  • mcgivormcgivor Posts: 2,063Solar Expert ✭✭✭✭
    Casement hinges.  Genius!  And, they're available in stainless.  Perfect.  Thanks.

    You're welcome.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • oldmakooldmako Posts: 14Registered Users ✭✭
    edited April 15 #6
    Yet another stupid question if you will allow......

    This project fell into an abyss last fall, but I am back at it.  I made a sweeeeeet bracket to hold the panel using your casement hinge idea.  Most of the year the panel will lie nearly flat on the boat's T-Top.  For winter storage I have Rube Goldberg'd a gizmo to orient the panel to the most advantageous angle of the dangle for my latitude.  It will also protect the panel (I hope) from wind gusts during winter and spring nor'easters which are common here in Virginia Beach.

    I bought a much higher quality charge controller based on recommendations from this site.   Many thanks, no sense in installing crap and then replacing it in 6 months.  I also bought two BLUE SEA systems 10 amp circuit breakers to protect and connect disconnect.  Another suggestion from someone here.    What a great site!   

    My questions regard wiring -

    1.  I assume that the positive lead from the solar panel goes to the first CB.  Where does the negative lead from the solar panel go? The batter neg I assume, but which battery?  I have two.  The circuit breaker has two leads and I ASSUME that both are HOT.  Current in- current out, right?  So, that big negative from the panel has to go somewhere.

    2.  This is the controller I bought... it's not in my hands just yet as I ordered it.  I am trying to obtain all the connectors etc that I will need since the boat is some distance away, and there are no nearby stores.

    Morningstar SS-10-12V SunSaver Solar Controller 10A 12VDC 

    I assume that the pos lead from the FIRST CB runs to the POS SOLAR on charge controller and that the pos lead FROM the CC BATT position runs to the SECOND CB.  Again, what about the negative leads?  Do I simply add one for each neg position? 

    Many thanks for any input.

  • EstragonEstragon Posts: 2,620Registered Users ✭✭✭✭
    The pv negative goes directly to the controller pv negative terminal, in a typical negative grounded system. The pv positive is wired to the controller positive via DC circuit breaker.

    Likewise the controller negative battery output goes to battery negative (or negative buss), and the positive to battery via DC breaker. Note that many DC breakers are polarized, with the terminal marked "+" connected to the source of *fault* current. In this case, the current source in a fault is the battery, not the controller (the *normal* operation current source).
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • mike95490mike95490 Posts: 7,797Solar Expert ✭✭✭✭
    Consider a trailer mounted bracket for the boat, charge while on trailer only ?
    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

    gen: ,

  • oldmakooldmako Posts: 14Registered Users ✭✭

    Oh hell, that makes perfect sense.  What was I thinking?   My CB's do not have any label WRT polarization, and only two lugs.   I assume one is current IN, and the other OUT.  So, that makes sense.  I can't wait to get this thing mounted.


    I am trying to make a permanent addition to the boat, one that does not involve any messing around while launching, or recovering the boat for storage.  I am trying to engineer the bracket for the panel so that it will be shock-absorptive when the boat is underway.  And, during a long day on the water, the panel will continue to provide topping off current to my cranking battery.  There are many occasions (hopefully!) when we are on the hook fishing with the engines off.   Baitwell, bilge and wash down pumps use a fair amount of current over a long day.  The stereo, not so much but you get the idea.  I want to install this once and reap the benefit when the boat is used often as well as when its laid up from late Nov-April.  Mounting the panel on the T-Top has the added benefit of placing it approx 14 feet above ground level.  

  • EstragonEstragon Posts: 2,620Registered Users ✭✭✭✭
    Bluesea does make AC breakers as well as DC - you may want to double check that it's a DC breaker. The breaker may also have polarity defined as "line" and "load" terminals.
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • dennis461dennis461 Posts: 106Registered Users ✭✭
    edited April 15 #11
    I have a single panel on the port bow handrail.  A cheap PWM controller and a fuse block.  Connected to battery.  All I run when fishing is the VHF and fish finder.  Since I only boat on sunny summer days, I do not worry about tilt and such.  Luckily, when parked in my yard, the panel faces almost South.

    Camden County, NJ, USA
    19 SW285 panels
    SE5000 inverter
    grid tied
  • oldmakooldmako Posts: 14Registered Users ✭✭
    edited April 27 #12
    One last question...I hope!

    Since I attempting to charge ('maintain' at a ready state is more like it) two batteries using one solar panel and one controller, can I simply parallel the batteries using the boats TWO onboard Perko (BAT OFF - 1 - 2 - ALL) switches?   In other words, when I leave the boat, and if I leave both Perko switches in the ALL position, both batteries will receive the panel's current, right?

    This is my plan - 

    1.  The output from the Morningstar charge controller will be hooked to just ONE (the closest) of the two, identical deep cycle batteries through a 10A ON/OFF type circuit breaker. 
    2.  When the boat is not in use, both Perko battery switches will be left in ALL.  PV charging current will be directed to BOTH batteries through the Perko switches in ALL, correct??

    I am in the habit of leaving the boat with both batteries OFF (to prevent unwanted discharge if I left something on, or something shorts in the ON position as bilge pumps are known to do on occasion), but with this setup, I want to keep the connection simple.  

    3.  After both engines are started, both battery switches will then be selected to their respective engine.  ie, One Perko in position1, the other in position 2 in order to isolate the two alternators and batteries.  This will remain while the boat is being operated.

    4.  During any potential LONG periods on the hook (with appliances running AND with the engines OFF) I will select one Perko switch off.  This will be done in an attempt to keep one battery fully charged and able to start an engine.  That will be the battery which is not connected to the charge controller.

    Clear as mud and correct or am I smokin' ganja and in serious need of help?

    Many thanks in advance.

  • EstragonEstragon Posts: 2,620Registered Users ✭✭✭✭
    I'm not clear on the need for two switches. On my boat, I have a house bank and a starting battery controlled by a single 1-2-all-none switch. It allows either or both banks to be charged (or discharged), in parallel, singly, or off, and the engine can be started from the house bank in the event of a problem with the starting battery.

    A potential issue with hooking up to one battery is that battery can be charged at a higher voltage than the other (because of voltage drop in wiring and connections), so you could overcharge one and/or undercharge the other. This may be less of an issue wiring a single switch to the controller, and using equal size and lengths of wire to each battery. Anyway, just a thought.
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • oldmakooldmako Posts: 14Registered Users ✭✭
    edited April 27 #14
    One switch per engine/battery.   

    You should be able to start either engine using either (or both batts in parallel) battery.  Once underway, the systems should operate independently of one another.  Hence the 1 - 2 selection on the Perkos.  The boat is already wired up in this manner, so I am just trying to figure out how to wire in the solar system.  And how to best utilize it. 

    If a schematic takes more than two colors to display a circuit, I'll be scratching my head and then cocking it like a dog watching TV.  Type s l o w l y for me.
  • EstragonEstragon Posts: 2,620Registered Users ✭✭✭✭
    So twin engines? I didn't quite catch that on first read, and I'm not sure I really understand how the existing wiring is done. If it works something like the way I think it does, I would go ahead and hook up the solar as you suggest.

    With the engines (and any loads) off and both switches on ALL, the batteries should be in parallel. With solar producing charging current, both batteries should rise to about 14.5-ish volts, measured at the battery posts. If these voltage measurements are within 0.1v (preferably identical, but 0.1 is about as accurate as a typical multimeter gets) the parallel connection is probably good enough for what you need. If out by more than that, either I've misunderstood how the wiring works (entirely possible), or there's a problem.

    BTW, I leave my bilge pump power on. I figure the risk of a dead battery is trumped by the risk of a sunk boat :smile:
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
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