Batteries discharging at night with no load on

christo1985
christo1985 Registered Users Posts: 8 ✭✭
in Solar Beginners Corner #1
I have mounted 3x160w Poly's on the roof of my bus, connected in parallel to a 60a mppt charge controller ' sun shield pro solar' feeding 3x100ah lead acid batteries, The distance between the panels and the charge controller is less than 15 feet using 10AWG from panels to controller and 4AWG from controller to batteries, batteries are also connected in parallel with a ground to the bus chassis, i also have a 2000w inverter connected to the batteries, but it is always switched off when not being used.
i have 6 led lights and a small water pump connected to this system, Maybe using 2 of the 6 lights for about 1-2 hours every night and the bars on the controller seen to go from 5 bars to 3 bars within this short amount of time? and at night it will go down as much as 1 bar with no load on....  the battery v never gets less than 12.8v but the bar's on the controller get down? 
Im not sure if i should change some settings on the controller or i have made a mistake with my wiring size or the battery bar indicator on the controller isn't accurate?
Any feedback would be great.... cheers
· Share on Twitter

Comments

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #2
    The wire size from panels to controller are a little on the small size and would give you about 5% volt drop using 160W×3×.75 (average output) ÷14.4V=25A and the linked volt drop calculator, you want to be 3% or less. Are the batteries flooded or sealed,AGM, deep cycle etcetera, that would give some indication of what the settings should be. The bars on the graphic are at best an indication of charge, usually whilst charging, ~14.4V being fully charged, if the voltage is at 12.8V with no load overnight, that would be normal. 
    http://www.calculator.net/voltage-drop-calculator.html
    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.
    · Share on Twitter
  • Thom
    Thom Solar Expert Posts: 196 ✭✭✭
    #3
    If using V I'd forget the "bars" and get a proper V meter. 12.6 in the morning is good 

    Thom 
    Off grid since 1984. 430w of panel, 300w suresine , 4 gc batteries 12v system, Rogue mpt3024 charge controller , air breeze windmill, Mikita 2400w generator . Added 2@ 100w panel with a midnight brat 
    · Share on Twitter
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #4
    Question, is this the controller you have, see link, the parallel arrangement would indicate a PWM not MPPT, also can you post the panel specifications on the back of the panels, always helpful 
    https://www.amazon.com/Ramsond-Sunshield-Charge-Controller-Regulator/dp/B009AI4LVM
    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.
    · Share on Twitter
  • christo1985
    christo1985 Registered Users Posts: 8 ✭✭
    #5
    I really appreciate all the feedback guys..
    I have attended a few pic's hopefully this will answer you questions.
    · Share on Twitter
  • christo1985
    christo1985 Registered Users Posts: 8 ✭✭
    #6
    Not sure if the pics successfully uploaded?
    · Share on Twitter
  • Aguarancher
    Aguarancher Solar Expert Posts: 315 ✭✭✭
    #7
    you need to first click on the tab that says 'attach image' to load a pic.
    · Share on Twitter
  • christo1985
    christo1985 Registered Users Posts: 8 ✭✭
    #8
    Ahhh I see
    · Share on Twitter
  • Aguarancher
    Aguarancher Solar Expert Posts: 315 ✭✭✭
    #9
    just an observation but the red wires should be on the positive side unless this is a positive ground system.
    · Share on Twitter
  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,115 ✭✭✭✭✭
    edited July 2017 #10
    One thing I notice is a li symbol in the bottom left corner of your CC screen. Is it set for Lithium ion batteries? As the voltage settles overnight it might think your battery is losing charge and giving you the less than full reading.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

    · Share on Twitter
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    edited July 2017 #11
    Good spot there @littleharbor2  pictures are worth a 1000 words.
    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.
    · Share on Twitter
  • christo1985
    christo1985 Registered Users Posts: 8 ✭✭
    #12
    That's funny.... the manufacturer told me the the LI battery stands for lead acid?
    Good spot, thank you for that. Should it be on GEL or something else?
    · Share on Twitter
  • christo1985
    christo1985 Registered Users Posts: 8 ✭✭
    #13
    Long story short, the red is now negative and black positive for the PV inlet, the angle of the photo also makes the load wires look like there in the wrong spot.
    · Share on Twitter
  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,115 ✭✭✭✭✭
    #14
    christo1985 said:
    That's funny.... the manufacturer told me the the LI battery stands for lead acid?
    Good spot, thank you for that. Should it be on GEL or something else?

    Don't know the ins and outs of your controller but  You should find in the manual an explanation.  FLA would be for conventional, Flooded Lead Acid. batteries AGM for sealed Absorb Glass Mat batteries. VRLA for sealed, Valve regulated Lead acid (AGM, Gel).batteries and Gel for .....you guessed it Gel batteries.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

    · Share on Twitter
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #15
    Christo, you now have the colours backwards....  in  wiring DC systems  the black is the negative and RED is the POSITIVE..... in AC wired  systems the BLACK is the POWER (+) and White is the common

     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
    · Share on Twitter
  • christo1985
    christo1985 Registered Users Posts: 8 ✭✭
    #16
    Hey west branch....
    When I did the wiring for the panels I made a mistake so I taped the ends, black is now positive and red negative, I know it's the other way around, amateur mistake
    · Share on Twitter
  • christo1985
    christo1985 Registered Users Posts: 8 ✭✭
    #17
    Thank you guys for the feedback! You have been awesome....
    I will change my battery type on my CC and see if that makes a difference ;)
    · Share on Twitter

Categories