Solar design help for DC powered boat lift

jimejoejimejoe Registered Users Posts: 12 ✭✭
I have a boat lift that uses 4 blower motors to raise it, displacing the water through a hole in the bottoms of the 4 separate tanks. It has four 12v 22ah batteries, 24v each side.  Only powers on for lift, one way check valve opens for lowering... what size solar kit would I need for this setup? Thanks,jim

Comments

  • mike95490mike95490 Solar Expert Posts: 8,813 ✭✭✭✭✭
    How long does each lift cycle last ?  How many cycles per day, or days between cycles ?
    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

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • BB.BB. Super Moderators, Administrators Posts: 30,633 admin
    How much current during operation (i.e. 2-5 amps @ 24 VDC for xx minutes by yy times per day, what seasons)?

    And where is the system installed... I get a couple locations from your IP address... Hendersonville Tennessee or Dallas Texas.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • jimejoejimejoe Registered Users Posts: 12 ✭✭
    About 2 minutes per lift, Hendersonville,tn
  • jimejoejimejoe Registered Users Posts: 12 ✭✭
    Use maybe 2-3 times a week 
  • jimejoejimejoe Registered Users Posts: 12 ✭✭
    This is the info I have 
  • mcgivormcgivor Solar Expert Posts: 3,426 ✭✭✭✭✭
    Two minutes is 0.03 of an hour, 100A × 0.03 = 3Ah so a 20W panel which produces ~1A would take around 4 hours to replace a single use, however it's not best to calculate marginally so double the panel wattage.

    Are the specifications for a single blower or for all four? 

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • jimejoejimejoe Registered Users Posts: 12 ✭✭
    I would think all four, I need help with the rest of the setup also, charge controller, 24v panel ? Thanks 
  • EstragonEstragon Registered Users Posts: 4,478 ✭✭✭✭✭
    In that size, most readily available panels will be nominal 12v (~18v Vmp at STC temp), so you'd likely want a pair of panels in series for Vmp of ~35v.  24v nominal battery will charge at something like 29v.  A smallish (~5a 12-24v) pwm controller would be needed.
    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
  • jimejoejimejoe Registered Users Posts: 12 ✭✭
    how many watts per panel 
  • mcgivormcgivor Solar Expert Posts: 3,426 ✭✭✭✭✭
    The specifications say 12V, not 24V, are you sure about the voltage? 
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery bank 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • BB.BB. Super Moderators, Administrators Posts: 30,633 admin
    It appears to be 24 volts for the motors (and the battery bank)... And it says 12 volts for lighting.

    Which is a question... How do they generate the 12 volt power. Is there a 24 to 12 volt down converter, or do they just take 12 volts off the 24 volt battery bank (not usually a good method--Can unbalance the two 12 volt batteries).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • jimejoejimejoe Registered Users Posts: 12 ✭✭
    I’m just simple minded, please dumb it down for me...what size panels do I need for charging four 12v 22ah batteries In series (24v), used 2-3 times a week, two minutes each time? Thanks 
  • BB.BB. Super Moderators, Administrators Posts: 30,633 admin
    edited July 2019 #14
    Are you looking at 4x charging setups or 1x charging setup charging all 4 batteries (can you wire from one panel to 4x batteries)?

    -Bill

    PS: What voltage are the battery banks (12 or 24 volt)? Just want to confirm (specifications say both 12 volts for lighting and 24 volts for lift).
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • EstragonEstragon Registered Users Posts: 4,478 ✭✭✭✭✭
    Assuming each side is independant (not connected together in parallel), you could do something like a pair of 10w 12v nominal panels and small controller for each side (4 x 10w panels and 2 controllers total).  If the sides are connected in parallel, maybe 2 x 20w panels and a single controller.

    The lights appear to be 500ma max, so I'd guess there's a voltage divider circuit to supply 12v?
    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
  • jimejoejimejoe Registered Users Posts: 12 ✭✭
    There is a electric charger that plugs in to just one plug and it charges all batteries. Two 12v tied together to make 24v on each side , I hope that answers your question. I would like to have just one charging setup for all ?
  • jimejoejimejoe Registered Users Posts: 12 ✭✭
    Do I need to answer everyone Individualy or just leave a comment ? Admin ?
  • BB.BB. Super Moderators, Administrators Posts: 30,633 admin
    Just one post that answers the questions for everyone is fine.

    Based on battery capacity, 5% to 13%+ rate of charge. 5% can work for sunny season/light usage. 10%+ is really recommended for best battery life.
    • 2x12volt in series = 24 volt
    • 2x 22 AH (at 24 volt) strings in parallel = 44 AH @ 24 volts
    • 44 AH * 29.0 volts charging * 1/0.77 panel+controller derating * 0.05 rate of charge = 69 Watt array minimum
    • 44 AH * 29.0 volts charging * 1/0.77 panel+controller derating * 0.10 rate of charge = 137 Watt array nominal
    • 44 AH * 29.0 volts charging * 1/0.77 panel+controller derating * 0.13 rate of charge = 178 Watt array "typical cost effective maximum"
    And then there is sizing the array based on your daily loads and hours of sun for your location.
    • 100 Amps * 0.03 hours (aka 2 minute cycle) * 1/2 cycle per day (once every 2 days) * 24 volts = 36 WattHours per day
    Solar energy for Nashville Tn, array, facing south:
    http://www.solarelectricityhandbook.com/solar-irradiance.html

    Nashville
    Average Solar Insolation figures

    Measured in kWh/m2/day onto a solar panel set at a 54° angle from vertical:
    (For best year-round performance)

    JanFebMarAprMayJun
    3.00
     
    3.51
     
    4.38
     
    5.02
     
    5.04
     
    5.13
     
    JulAugSepOctNovDec
    5.22
     
    5.14
     
    5.13
     
    4.70
     
    3.52
     
    2.87
     

    Worst case is 2.87 hours (long term average sun) for December:
    • 36 WH per day * 1/0.52 off grid system eff * 1/2.87 hours of sun per day (Dec) = 24 Watt array "December breakeven"
    I would suggest a minimum of 2x "predicted harvest" to account for bad weather and extra cycles during nice weather... Or 2x24=48 Watt panel minimum.

    And if we go back to what 5% minimum rate of charge = 69 Watt minimum array (recommended for better battery health) with 137 Watt array also being a good choice (best for battery charging).
    • 69 watt / 29.0 volts charging = 2.4 Amps charging current

    You are looking at something a little "different' for a solar power system... A relatively low power 24 volt charging system. You either need a "12 volt" solar panel (Vmp~18 volts) and ~69 Watts (suggested) and a "boost type" charge controller:

    https://sunforgellc.com/gvb-8/ (something like $170 -- not cheap)

    With a ~69 Watt array

    Or get a standard PWM Solar Charge Controller (pulse width modulated) which are much less expensive and 2x Vmp~18 volts ~35 Watt solar panels in series (for a ~70 Watt Vmp~36 volt solar array).

    The actual size of the array at ~69 Watts minimum is just that, you could go as high as 180 Watt array (two ~90 Watt panels in series) just fine... Just depends on what you can get for a reasonable price.

    https://www.solar-electric.com/residential/solar-panels.html?p=3&product_list_order=watts

    Smaller solar panels tend to be more expensive--So do a couple configurations (including cost of shipping, if shipped) to see what works out best for your.

    I suggest "glass" based crystalline panels (mono or poly) as having the best life... However they are glass and if you have vandalism issues, then possibly a flexible panel may be a better choice (but they last probably 2-7 years vs 20+ years for glass).

    -Bill

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • jimejoejimejoe Registered Users Posts: 12 ✭✭
    Wow, that’s a a lot of info, thanks for taking the time... what about the harbor freight 100w kit ? Just wondering ?
  • jimejoejimejoe Registered Users Posts: 12 ✭✭
  • jimejoejimejoe Registered Users Posts: 12 ✭✭
    The first pic is one side the second is the controller side
  • BB.BB. Super Moderators, Administrators Posts: 30,633 admin
    Guessing this is the Harbor Freight kit you are asking about?

    https://www.harborfreight.com/100-watt-solar-panel-kit-63585.html
    • Four 25 watt solar panels give you plenty of clean, quiet energy
    • Amorphous silicon solar cells for maximum output in both bright and cloudy conditions
    In my humble opinion, I would not use Amorphous panels (or at least these panels). They have a history of failing in 6 months to a year (or at least dramatic loss in output). Crystalline (the round/squarish black or "fractured blue" looking cells) last much longer under a glass face.

    The other question we have dodged for the moment... I don't know anything about the controller and wiring of your system.

    You have two choices--You feed "unregulated" solar panel power (around Vmp~36 volts, but realistically from zero volts (night) to 45-50 VDC -- Voc Voltage open circuit) and there is a "charge controller/regulator already in the system to charge the batteries--OR you feed (more or less) regulated 28.8 volts (if those are sealed/AGM batteries) directly to the battery buses (no switches, no downstream regulator, diodes, etc.--Must be directly connected to batteries).

    And most solar charge controllers must connect directly to the live battery bus so they can power their internal electronics and measure the battery voltage (to make charging decisions). And you connect the solar panels last (powering a solar charge controller from solar panels and no battery connection can confuse or even damage the solar charge controller).

    Do you have any information on what the Charging Input to your boat lift system is/requires? You can post a link to the system/manual if you have one available (links are OK when directly asking/answering questions--We try to avoid "free advertising" since our forum host who pays the bills is a solar retailer/wholesaler).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • EstragonEstragon Registered Users Posts: 4,478 ✭✭✭✭✭
    Does the HF kit do 24v charging?

    The battery in the pic is some kind of sealed lead acid, most likely AGM, most likely with an absorb charging voltage of ~28.8v.  The label says to only charge with their charger though, so you may want to confirm proper absorb/max charging voltage to be sure the charge controller is compatible.
    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
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