300 watt solar panels and 600ah battery bank only lasting one day?

chriselkschriselks Posts: 6Registered Users ✭✭
Looking for tips on improving my overall system right now I have 3/100watt panels wired in parallel into a tracer 30amp mppt controller and feeding 6 101 ah deep cycle batteries only running low watt led lights mostly and it only lasts about 2 days total

Comments

  • PhotowhitPhotowhit Posts: 4,530Solar Expert ✭✭✭✭
    6 - 12 volt?

    You are quite a bit under paneled, most manufactures want at least a 10% charge rate, you have about 225/14= 16 amps available to charge a 600 amp bank or about 16/600= 2.6% charge rate.


    Watt is the total wattage of the lights? are they AC lights? are you running an inverter as well?
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • chriselkschriselks Posts: 6Registered Users ✭✭
    edited June 13 #3
    They are AC lights 9 Watts a piece and there are 5 I’m running a 1200 watt modified sine inverter it’s all 12v. How many panels do you recommend to get me where I need to be? I’m new to all this so bear with me
  • chriselkschriselks Posts: 6Registered Users ✭✭
    I have a 24 volt inverter on the way so the whole system will be 24 v soon
  • EstragonEstragon Posts: 2,310Registered Users ✭✭✭✭
    One issue may be the voltage of the panels in parallel (especially if they're warm/hot) may be too low for an mppt controller to use for charging. Series wiring may help if the 100w panels are a typical nominal 12v (~18vmp). You would need to check the open circuit voltage maximum voltage the controller will take to see if the three panels could be wired in series. If you end up going to 24v, the parallel wiring won't work.

    Getting a system that works well for you always starts with loads. What is the system going to run, and how many hours/day?

    A good sized 24v inverter could use about as much just being on as your lights use. If you run the lights 12hrs/day, the load is 9 x 5 =45w x 12hrs = 540w. Battery power required for losses plus load could double that.

    The lights themselves may be DC, using a small transformer (wall wart) to go from 120vac to (likely) 12vdc. Running the light directly off DC might make more sense if the lights and batteries are fairly close together.

    Anyway, it would help to know more about intended loads before going further.
    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
  • chriselkschriselks Posts: 6Registered Users ✭✭
    As of now I’m getting 17volts and 8-9 amps with all 3 panels wired in parallel. It’s running a completely off grid tiny home. We run light for a few hours during the day and a fan at night every day and about 1-2 hours of tv(led 32 inch pulls 30 Watts at 120v) would like to be able to upscale to run a small refrigerator if possible
  • mike95490mike95490 Posts: 7,642Solar Expert ✭✭✭✭
    adding a small fridge will nearly require going to 24V with all the other loads you have.  And a bunch more panels,
    you will eventually have a 24V 300ah bank, which needs 30A to properly charge.  That would require about 1,000w of panels.

    Currently, the system you put together is not well engineered, and that's why the batteries go dead.  Since that's happening, your current batch of batteries is likely toast.   Get them charged up from your generator, and maybe by using $20 of fuel, you can save $600 of batteries.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • chriselkschriselks Posts: 6Registered Users ✭✭
    My next question is how much panel will my 30 amp mppt tracer 3210 be able to handle at 24v would I be able to run 4 270 watt 24v panels?
  • littleharbor2littleharbor2 Posts: 914Solar Expert ✭✭✭✭
    This should help

    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, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • PhotowhitPhotowhit Posts: 4,530Solar Expert ✭✭✭✭
    A little help reading the chart, the max rate of charge would be 780 watts at 24 volts. Since panels can only produce about 75% of their rated wattage you can be expect to get pretty much maximum value (cost effective) from an array up to 1040 watts (75% of 1040 = 780) so you would be about at the max for the charge controller at 1080 with little waste on a 30 amp charge controller at 24 volts.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • chriselkschriselks Posts: 6Registered Users ✭✭
    So that would be the most effective for me. I’m going to be ordering 4/270 watt panels from renogy today and I will repurpose my 100 watt panels elsewhere. Thank you all so much any other helpful info would be appreciated
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