Charging one battery with solar panel and outboard alternator on sailboat

I'd like some opinions on the best way to connect these two charging sources to the battery.  Is it ok to run the solar panel and outboard alternator into a solar panel controller?  Would it be better to have a separate controller for each one?  Will a solar controller function correctly with input from an outboard motor alternator?

Thanks.

Comments

  • EstragonEstragon Posts: 2,047Registered Users ✭✭✭✭
    You would connect the alternator directly to the battery. It should have its own regulation. Charge controllers aren't normally designed to handle alternator output.
    Off-grid.  
    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
  • softdownsoftdown Posts: 1,754Solar Expert ✭✭✭✭
    I second Estragons offering.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • rporterrporter Posts: 3Registered Users
    Its a 6hp outboard with an "alternator" which looks like two coils that fit under the flywheel and there is a rectifier.  The only info I can find is that the output is about 5 amps.  Do you think the rectifier has capability to regulate the charge rate?  I don't want to over-charge the battery if I'm running the engine for 8 hours.
  • softdownsoftdown Posts: 1,754Solar Expert ✭✭✭✭
    I should think you could measure the output from the alternator and see if it tapers off as the battery approaches full charge. If it is so simple that it does not, I should think (more often really) that one could find a simple gadget that would moderate the output. Bear in mind that I am doing some speculation here.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • jonrjonr Posts: 930Solar Expert ✭✭✭✭
    edited March 2017 #6
    Perhaps of interest for unregulated alternators:

    http://www.boatingmag.com/converting-your-outboards-unregulated-charging-system

    You know you are unregulated if the battery voltage goes too high (eventually, with no loads).
  • EstragonEstragon Posts: 2,047Registered Users ✭✭✭✭
    What kind of battery and bank size are you charging? Do you know the voltage on the alternator output?
    Off-grid.  
    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: 99Registered Users ✭✭
    Do you know make, model, year of outboard?  From your description it sounds like the rudimentary system used on 1960-1970 vintage two stroke motorcycles.  The main source of regulation was the battery itself. The magneto-coil-rectifier setup simply sent pulses of DC to the battery.  If the battery lost all it water (like when the dirt bike falls over) the pulses of DC would be high enough to burn out the lights in short order.
    Camden County, NJ, USA
    19 SW285 panels
    SE5000 inverter
    grid tied
  • oil pan 4oil pan 4 Posts: 669Solar Expert ✭✭✭✭
    If you have an oversized battery for running lights at night or a secondary electric motor then 5 amps is probably not enough to come close to keeping the battery fully charged.

    Solar hybrid gasoline generator, 7kw gas, 180 watts of solar, Morningstar 15 amp MPPT, group 31 AGM, 900 watt kisae inverter.

    Solar roof top GMC suburban, a normal 3/4 ton suburban with 180 watts of panels on the roof and 10 amp genasun MPPT, 2000w samlex pure sine wave inverter, 12v gast and ARB air compressors.

  • jonrjonr Posts: 930Solar Expert ✭✭✭✭
    edited March 2017 #10
    In theory, a DC-DC converter (as is found in the better solar charge controllers) could take excessive voltage from a simple permanent magnet alternator and convert it into additional current.   My understanding is that most small engines use a shunt regulator (briefly shorting out the windings to reduce voltage).

    My guess is that one could connect the output of the alternator+rectifier to a solar charge controller.  But only if the peak (not rms) open circuit voltage of the alternator was less than the charge controller's max input voltage.
  • oil pan 4oil pan 4 Posts: 669Solar Expert ✭✭✭✭
    I have seen simple magneto generators put out up to 24v OCV with the battery removed, with an otherwise functional regulator. Straight off the magneto can produce up to 48VAC at no load.
    I'm not saying every single one is like this, but I have seen a few.

    Solar hybrid gasoline generator, 7kw gas, 180 watts of solar, Morningstar 15 amp MPPT, group 31 AGM, 900 watt kisae inverter.

    Solar roof top GMC suburban, a normal 3/4 ton suburban with 180 watts of panels on the roof and 10 amp genasun MPPT, 2000w samlex pure sine wave inverter, 12v gast and ARB air compressors.

  • jonrjonr Posts: 930Solar Expert ✭✭✭✭
    So for that generator, maybe 68V peak.  OK for some solar charge controllers.

    Last summer, I blew an ignition module surge protector/fuse.  Apparently because the bad battery wasn't accepting much charge (and the regulator wasn't regulating very well).
  • rporterrporter Posts: 3Registered Users
    Update a year later.

     Currently I use the solar panel or the outboard charger separately.  I would still like to combine the wiring so the outboard charger runs through the controller.  I have posed the question to Morningstar. (Sunsaver 10).

    And I just received an answer but no reason given, "do not connect the outboard charger to the the controller".

    The outboard charger had a voltage limiting system built in.  I have installed a voltage meter reading to two decimal places.  The voltage is cut off at about 14.65 volts.  My concern is overcharging the battery if the motor is running 8 or 10 hours.
  • HorseflyHorsefly Posts: 294Registered Users ✭✭✭
    edited March 31 #14
    As others have said, let the Morningstar controller handle the solar. The alternator should be a separate, parallel charge source. My sister's sailboat has a 100A alternator that does lots of duty charging the house battery. It goes thought a Balmar ARS-5, which turns the alternator power into a three-stage charging source for the AGM batteries.  Then you don't need to worry about over-charging from the alternator. When the battery is full, the ARS-5 will lower the regulated output voltage to float.

    I think my sister and brother-in-law are not real happy with the Balmar, but it's mainly because it is a challenge to program. I think once it works fine it works fine.
    Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 4 x Vmax XTR12-155 12V, 155AH batteries in a 2x2 24V 310AH bank.
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