M50 meter ?s

antiquepedaler
antiquepedaler Registered Users Posts: 1
I used Power  down to 10.5 running the furnace.  Now the meter shows an X over the battery. The system seems to be charging as I’m showing 11.8. But the X is still there.  Also the battery picture has never shown more than half full. What do I need to do?

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    edited January 2020 #2
    Welcome to the forum AP,

    I am not sure what the "X" is based on... So, lets do some basic debugging.

    If you have a volt meter, check the battery voltage. Does it read ~12.4 volts too? If yes, at least the display is correct.

    How big is your battery (12 volts at XXX Amp*Hours)? What is your solar a-rray Wattage?

    Many times, when a charge controller sees the battery fall below ~10.5 volts (sometimes 11.5 volts, depends on configuration), it will turn of the LVD output (low voltage disconnect). The Charge Controller will not turn on the LVD output until the battery is >~12.7 volts (battery is being successfully/actively recharged).

    So, it may keep the LVD off until the battery bus voltage is >12.7 volts, and then the "X" should then disappear (guessing). The battery is still discharged, but it is on its way to recovering. To fully recharge the battery, you will need to see the bus voltage hit the absorb set point (~14.4 to 14.8 volts) and be held there for something like 4-6 hour to get the battery back to 100% State of Charge.

    Knowing your solar array wattage, assuming middle of the day, sunny weather, clear of shading, etc., we can estimate the typical charging current (i.e., is 6.5 amps charging "good or bad"):
    • 6.5 amps * 12.4 volts = 80.6 Watts
    Which, if middle of day, pointing roughly towards sun your array would be somewhere around 80-160 Watts... If you have a 500 Watt array, and sunny conditions, middle of the day, etc..., then 6.5 amps is "not good enough" charging current and needs further debugging.

    And then based on AH of the battery bank... If 100 AH 12 volt battery bank taken to dead:
    • 100 AH * 1/6.5 Amps = 15 Hours of "charging" or 2-3 days at least (plus another ~3-6 hours of 14.x volts absorb)
    Anyway, that is how the basic math works.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    What kind of battery, Lead Acid or Lithium ?
    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 ,