12V battery solar charger

Discussion in 'Power Electronics' started by Pai, Aug 28, 2016.

  1. Pai

    Thread Starter New Member

    Aug 28, 2016
    Hello everyone

    Im new to this forum from South Africa, doing a small hydroponic project for developing rural settlements who struggle during the crop season! and would like to know if the following items I want to get will work well together. Its basically a solar powered hydroponic tower. I tried to give as much information as possible and drew a picture on how i would put it all together lol ¯\_(ツ)_/¯ idk (Attached!)

    12v 7AH Rechargeable valve regulated sealed battery
    Constant voltage charge
    Voltage regulation standby use 13.50-13.80v
    Cycle use 14.40-14.70v

    Solar charge controller
    Rated load current 10A
    Rated charge current 10A
    Work voltage 12/24v

    Water pump
    Voltage DC 6v ~ 12v : 18W
    Head height 1.5 - 7m
    Flow 246 - 800L/H

    PC Fan
    DC 12v

    Control power timer switch (it would be every 20min 24/7)
    Rated Voltage:12V DC
    Full Time Range:1Min-168Hours
    Contact Capacity: 16A(8)A,250V AC
    Resistance load: 16A
    Inductive load: 8A
    Internal battery:1.2V/40mA(rechargeable batteries)
    Operate Temperature:-10~+40°C
    Programmable:17times(week or day)
    Minimum interval:1 minute

    Solar panel

    Normal Power – 20W
    Normal Power Voltage – 17.5 V (±0.5V)
    Normal Power Current Impp (A) – 1.1 A
    Open Circuit Voltage – 21 to 22 V
    Short Circuit Current – 1.3 A

    L.E.D's x3

    ( ͡° ͜ʖ ͡°)................................................................................lol
    if my drawing offends you im sorry:p


    Last edited: Aug 28, 2016
  2. ScottWang


    Aug 23, 2012
    So, you already bought all the stuffs or you want to build them?

    >Control power timer switch (it would be every 20min 24/7)
    What's the meaning of 24/7?

    >Programmable : 17times(week or day)
    More details.

    >Normal Power Current Impp (A) – 1.1 A
    What's the meaning of Impp? (Amp, Input or what)

    According to the block diagram, the device on the right side, they all connected in series, I think their could be have a problem, could you explain all the details according to block diagram, such as when the timer time up what will be happen, and according to what condition to set the timer, what time the water pump, pc fan, led will be active, you didn't describe the spec of leds.
  3. Pai

    Thread Starter New Member

    Aug 28, 2016
  4. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    24/7 means 24 hrs, 7days a week
    ScottWang likes this.
  5. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    Hmmm !
    A 12V 7AH battery requires 0.7A Current limited charger so that battery life can be maximized, so I would chose a solar charger of around 1 to 2 Amps to cut down cost. A 10 amp Charger is overkill.
    plus the charger needs to be a SLA charger type since they require a constant current to charge at max of ~13.85VDC.
    Other than that you are good I believe.
    Plus everything needs to be connected in parallel.
    The LED details are needed as like, RED, GREEN etc. Since different colors take different voltages. You can connect 3 of them in series ( 12V supply ) but still you will need a series resistor which can be identified once you chose the LED color and type (assuming 5mm standard LED)

    PS.. the pump will be connected to Timer (so not all in parallel)
    and if you like to charge the battery at low sun light, you might need to find a panel than can supply ~20V at 1A in that level of sunlight. But the panel you describe will work in Good Sunlight
    Last edited: Aug 29, 2016
  6. ScottWang


    Aug 23, 2012
    I thought something like that, but I can't figure out the real meaning, so the timer can be setup to one week long and repeatedly?
  7. Bernard

    AAC Fanatic!

    Aug 7, 2008
    Average drain about 1 A @ 50 % duty. One day = 24 Ah. Needed battery maybe 2X = 48 Ah.
    Solar panel needed, 48 Ah / 8 h. of sun = 6 A, or about 72 W.
    Timer, 555 IC & relay.
    Review of figures is suggested.