PV Charge Controller for 12V lead acid battery

Discussion in 'General Electronics Chat' started by hina gohar1302, Apr 30, 2014.

  1. hina gohar1302

    Thread Starter New Member

    Feb 7, 2014
    I have to design and simulate solar charge controller for 12V lead acid battery.
    input to charge controller comes from solar panel and charge controller has to provide constant 12V on its output i.e. across C2 capacitor...after charge controller there is lead acid battery charging circuit which I took from Electronic Devices book by Boylstat..in between charge controller and battery charging circuit there would be blocking diode or switch which will connect when charging and disconnects during discharging...
    I need help in calculation and analysis of this last part of lead acid battery charging circuit i.e. current estimation,power and voltage..on Collector terminal there will be battery connected and ground I also showed coz after this battery we have dc load and plus inverter for ac load...
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
    Dont think it will work, the transistor charging is in constant current mode,you need to charge lead acids with constant voltage, better to use an off the shelf regulator like Lm317k, or Lm7812.
  3. alfacliff

    Well-Known Member

    Dec 13, 2013
    actually an amplified zener across the battery ( shunt regulator) is what is used on a lot of solar charge controllers.
  4. wayneh


    Sep 9, 2010
    For what it's worth, a 12V lead battery is considered discharged by the time its voltage drops to 12V. You need at least 13V at the charger output to trickle charge and ideally up to ~15V when the battery needs a fast bulk charge.

    Using 2 blocking diodes on the PV panel wastes twice as much power as using one.
  5. hina gohar1302

    Thread Starter New Member

    Feb 7, 2014
    Shelf regulator battery instead of what to be used there...
    if it will not work then how it will work..
    this solar charge controller will run 40W dc load ..means after battery there will be dc load which requires 12V..
    charge controller output will not be 12V battery has to charged till 12V..charge controller output will be double i.e. across C2 according to input on charge controller