Having issues running the load in my solar system

JHarb14JHarb14 Posts: 3Registered Users
Hello, I had just recently bought a small solar panel system so that I can learn more about solar, and to also run my small pond water pump. I got a small solar panel and a sort of cheap charge controller. I have 2 12 volt batteries that i was eventually going to wire up in either series or parallel. I have had these batteries sitting for a while, but both are in good shape.
The issue i am having is that when i hook up the solar panel, a battery and the load, the charge controller says the solar panel is charging the battery, but the load does not work. I have had it out in the sun for the past few days, and nothing has changed. The load light is on, but the arrow that means it is being powered is off. How can i fix this?

Comments

  • mike95490mike95490 Posts: 7,646Solar Expert ✭✭✭✭
    Try connecting the Load to the battery, and not the terminals on the controller.   Many controllers don't have very beefy outputs, and can't run a large load.
    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

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  • littleharbor2littleharbor2 Posts: 914Solar Expert ✭✭✭✭
    edited August 2017 #3
     Most inexpensive controllers with load control terminals are intended to power lighting at night They are configurable for different time durations and some have a 24 hour setting. The key here is for lighting they are triggered by darkness. If you want to use this feature during daylight hours you need to set it to do 24 hour output. One benefit to using the load connections on the controller is that the controller will shut down the load if the battery becomes dangerously discharged. These load terminals are really not designed to run any substantial loads.
      As Mike95490 said, connect directly to the battery.

    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.

  • JHarb14JHarb14 Posts: 3Registered Users
    So for the past few days i had figured out why the load was not working; the pump was faulty. The issue i'm having now is the load won't stay on the whole time. I had set it to 24 hour mode, but after a few hours it shuts off. On the screen of the charge controller, the battery blinks, and if i want to turn it on again i have to hold down 2 buttons, then the battery bars come on again and the load works. This is annoying and i would just like the load to stay on all the time. The battery never gets below 11 volts. Thanks
  • littleharbor2littleharbor2 Posts: 914Solar Expert ✭✭✭✭
    Sounds like you have battery problems. How old is your battery? Did you get it new? You mentioned they were sitting around a while, not good for flooded batteries especially. Were they fully charged before you hooked them up/ Have they ever been equalized? You should try to never go below about 12 volts.

    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.

  • EstragonEstragon Posts: 2,310Registered Users ✭✭✭✭
    11 volts is almost completely discharged. Any significant load at that state of charge is likely taking voltage below the controller's low voltage cut-off. The controller disconnects the load to protect itself from the low voltage, and to prevent permanent damage to the battery.

    My guess is pressing the buttons resets the controller, which sees a voltage with no load above cut-off and starts working, which sucks voltage down again, and so on.

    I suggest disconnecting the load, and fully charging the battery ASAP. Fully charged, the battery should stay at 12.8v if left sitting overnight with no charging source. While charging, battery voltage should get up to around 14.5v and stay there for 2-3 hours.

    It would help if you could list the running current of the pump, the wattage of panel charging, and battery type and capacity.
    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
  • JHarb14JHarb14 Posts: 3Registered Users
    I fully charged the battery last night and it is now at 12.8 volts. The solar panel is 20 watts. The power consumption is [email protected] ~ [email protected] (currently running 12v, but would like to run 24v if possible to get more power through my waterfall) and the battery is a 12v 7ah battery. It still shuts off during the night time. Do i need a larger battery?
  • EstragonEstragon Posts: 2,310Registered Users ✭✭✭✭
    Probably. 12v times 7ah is 84 watt-hours, but you generally can't use 100% of capacity. Using more than about 50% is hard on a true deep-cycle battery, which yours may not be. It quite likely has some degree of sulfation, so its functional capacity is likely lower than 7ah.

    Assuming the [email protected] load is correct (did you measure it, or is that a rating?), you would be under 50% charge after about 9hrs. My guess is the 5w is a minimum and the actual draw is higher, so 9hrs is probably optimistic.

    The 20w panel, might produce about 1a charging current. Most locations get something like 4-5hrs of average daily full sun equivalent - less if the panel is not correctly angled or has any shade, so it would likely be borderline able to charge the battery some days, and not able to on others. It would not likely be able to catch up on charging the battery from a very low state of charge.

    For your higher powered waterfall - roughly [email protected] for a couple of cloudy days would be something like 48ah. You would want twice that to avoid drawing down below 50%, so roughly [email protected] To recharge that you'd want enough panel to give you around [email protected] so a couple of 100ish watt 12v panels in series, or a 250ish watt 24v panel.
    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
  • fratermusfratermus Posts: 20Registered Users ✭✭
    One benefit to using the load connections on the controller is that the controller will shut down the load if the battery becomes dangerously discharged. These load terminals are really not designed to run any substantial loads.
    For the OP's benefit:  running a relay off the LOAD output would preserve the low voltage disconnect function while allowing higher current loads.
    2017 Promaster 159" DIY camper
    570W mono / 220AH GC
  • mcgivormcgivor Posts: 1,749Registered Users ✭✭✭✭
    fratermus said:
    One benefit to using the load connections on the controller is that the controller will shut down the load if the battery becomes dangerously discharged. These load terminals are really not designed to run any substantial loads.
    For the OP's benefit:  running a relay off the LOAD output would preserve the low voltage disconnect function while allowing higher current loads.


    Valid point, preserving low voltage cutout protection whilst allowing larger loads, perhaps installing a diode across the coil would be a useful addition to snub the collapsing reverse EMF from damaging the controller when the relay drops. Just a thought.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

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