Controller for a 24 v pump system + battery bank

mrichterdmrichterd Registered Users Posts: 3
edited January 2017 in Solar Water Pumping #1
Hi, i need some help, i have 4 simple pump systems (direct whit lcb), now i need to pump 18 hours a day, so i buy in a local store the panels, a mppt controller (seller say its ok) and one par of batteries. the controller its a Fangpusun 100/15, my pump its 8 amp, so i thing was ok.
Whit this type of controller can i connect my pump to the load connectors? somebody say to me that this connectors are only for "lights", not fot a electric motor, and that its better if i conect the pump direct to de baterry banck. If i make this i can every day consume the total charge of the batteries, and that was not the idea.


  • BB.BB. Super Moderators, Administrators Posts: 31,684 admin
    This is going to be a bit difficult system to make inexpensive and reliable.

    I like to start with the loads (amps * volts * hours of operation per day = Watt*Hours). And trying for the minimum amount load energy possible.

    It is possible to connect the pump motor/LCB (Linear Current Booster) directly the the controller--But you have to watch for how much current the pump(s) draw during start up too. You would like the controller to turn off the load if the battery voltage falls to ~11.5 volts (under load--just a guess--Lead Acid battery voltage varies on state of charge, temperature, loads/charging current, age, etc.).

    Ideally, if you could pump to a tank/cistern with "more pumps+solar" during the ~4-6 hours of sun, and let the pressure of the water in the the tank supply the water+pressure for the other 12 hours.
    If you need the powered pump (circulation for pond/aquaculture) for 18 hours per day--That is going to be more difficult/expensive with solar.

    More or less, standard Lead Acid deep cycle batteries can only be fully recharged if they are taken down to 75% state of charge a day. If you take it down to 50% in one day, it takes ~2 days of full sun to recharge.

    Your battery bank should supply about 2 days of "no sun" and 50% maximum discharge--Or about 4x your daily loads.

    The solar array should be sized to supply 5% to ~13% charging current (i.e., 100 AH battery, 5 to 13 amps charging). And if this is a daily use system, I would suggest 10%+ as a minimum. Note that if you are pumping during the day--Say 8 amps, that means 13 amps charging + 8 amps load = ~ 21 amps from solar array.

    A battery powered pumping system ends up being more more expensive and more maintenance (battery) than a pure solar+pump system--But if you need 18 hours of pumping--That is what you need.

    So--How many Amp*Hours or Watt*Hours per day do you need? Is this a 12 month a year system or 6-9 month a year system (non-winter/poor sun)?

    Roughly, where will the system be installed? Need to figure out your hours of sun per day (are you in Santiago, Chile?).

    Average Solar Insolation figures

    Measured in kWh/m2/day onto a solar panel set at a 57° angle from Vertical:
    (For best year-round performance)
    Jan Feb Mar Apr May Jun
    Jul Aug Sep Oct Nov Dec
    If this is your location, you have lots of sun--It will make this a bit easier.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mrichterdmrichterd Registered Users Posts: 3

    Bill, thanks, thats is a very goog answer, here more info:
    i have buy 2 200w 24v pannels, 2 EnerSys PowerSafe 12V170F Battery (170 Ah) whit 1 year of use. and a Fangpusun 100V 15a controller. The pump its a aquatec 5501, whit operation courrent = 3 Amp (i like to connect 2 pumps in parallel). I dont know the start courrent of the pump. 
    Location its Osorno -40.58 -73.13
    Jan   6.07
    Feb   6.00
    Mar   5.07
    Apr   3.80
    May 2.83
    Jun 2.33
    Jul  2.68
    Aug  3.21
    Sep 4.25
    Oct  4.96
    Nov  5.4
    Dec  5.89

    The optimal for me its 12 to 18 hours of pumping, But in this case the question its reverse, how many hours can i pump whit this system or maybe i need to buy more pannels and baterries.
    And how can i contect the pump (s) controller and batteries.

    My adventage is that this system its for beef cattle, so, the days whit more sun, more consume but more production to.

    Here in Chile there are not many experts on small solar systems, so i let me advise by the seller, but finally he just gave me a handmade drawing... And i have not been to find a quality text that will help me to size and diagram my system.
    (sorry by my english, i write like Tarzan, i hope you can understand me.)
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