Load amps vs battery charging amps

mountainmanmountainman Posts: 59Registered Users ✭✭
With 400 watt array on pwm Why is it that I get 16 peak amps charging a 50% soc battery bank. and with a full battery 22-24 amp peaks running an inverted 250 watt heat light.

Comments

  • BB.BB. Posts: 27,351Super Moderators admin
    What is the absorb charging voltage when 16 amps and 50% soc?

    What is the battery bank ah capacity? How do you know 50% soc?

    If the charging voltage is around 14.75 volts and 16 amps (flooded cell lead acid), then possibly a sulfated battery.

    Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mountainmanmountainman Posts: 59Registered Users ✭✭
    1.172 sg 50% 208 amp hr 2 6 volt new batteries. 12.6 volts around 200 watts (14.1 308 watts 250 watt load) fla batt
  • BB.BB. Posts: 27,351Super Moderators admin
    edited April 25 #4
    Charging at 12.6 volts at the battery and 16 Amp in full near noontime sun?

    I am not sure why. If you get 22+ amps from the charge controller at 14.1 volts under same sun conditions running a load, then charging should be the same maximum current from controller.

    Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • EstragonEstragon Posts: 2,219Registered Users ✭✭✭✭
    I'm not sure either. I'm assuming the current is being measured at a shunt on the controller output to battery? Voltage measured at the battery? So voltage at the battery posts goes up from 12.6 to 14.1 when you turn on the load? Does it go back down to 12.6 when you turn the load off, and back to 14.1 when you turn it back on (and so on. In other words, is the observation repeatable)?
    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
  • mountainmanmountainman Posts: 59Registered Users ✭✭
    I'm using rc meters on the battery 1 from controller cables to batt and 1 from batt to loads and yes it goes back down when I turn off the load at solar noon. My thoughts were internal resistance of the battery. But I'm new to solar battery charging.
  • BB.BB. Posts: 27,351Super Moderators admin
    Really need to know battery terminal voltage(s) and current flowing into the battery... I.e., was it 12.x volts @ 16 amps, or 14.xx volts @ 16 amps and 50% state of charge.

    I am not quite sure I am clear on what is happening.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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