Same sun different charge rates

Plucka
Plucka Registered Users Posts: 130 ✭✭
Yesterday lithium batteries were 13 volts @ 9 am and solar mppt charger was putting in 17.6 amps.                                                                         Today same weather batteries were 13.3 volts @ 9 am but charger was only putting in   15.6 amps .Is this normal or has a bird done it's business on my panels?            

Comments

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Higher voltage lower current, day to day temperature difference, different state of charge to mention a few possibilities, not something to be over concerned with, IMHO.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    As mcgivor notes, within normal day-to-day variation. If worried about a bird bomb, by all means go look with a damp sponge. Could also be an errant leaf or twig. I'd also ignore it unless it was a persistent problem.
    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
  • Plucka
    Plucka Registered Users Posts: 130 ✭✭
    edited August 2018 #4
    today  is cooler -probally the difference. thanks