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maria_bettina's avatar
maria_bettina
Explorer
Jul 22, 2022

Renogy 20A MPPT Controller- electrical/amp question

I've been watching the display on the solar controller for a few days now. Our TC is parked at home, not on shore power but is sitting outside with the 3@100 watt solar panels charging the 200Ah deep cycle battery. The only electrical appliance that should be drawing current is the Renogy unit itself. The elec fridge is unplugged, nothing else plugged in, no electronic devices being charged.

At about 1:00 p.m. today I noticed that the display showed that about 0.5A are being drawn...but for what?

The Renogy unit itself uses <100mA (so 0.1A?) as I recall (for lights/display), so I am worried there is a short somewhere.

What can be causing that high usage and is it something to worry about? Does a battery need that much juice during the float stage?

PS It's in the upper 90's here, so maybe that's an issue?
Truck Campers
  • Lwiddis's avatar
    Lwiddis
    Explorer II
    Jul 22, 2022
    Half an amp isn’t high use IMO. Smoke detector, co2 detector, entertainment center, TV booster etc.
  • time2roll's avatar
    time2roll
    Nomad
    Jul 22, 2022
    1/2%C would be a normal draw when full. 200Ah would be 1 amp. I call full and normal and probably floating.

    Float closer to 13.1-13.3 is plenty in the heat. Does the MPPT have a temp sensor or ambient temp compensation? What is the voltage on the battery terminals?
  • StirCrazy's avatar
    StirCrazy
    Moderator
    Jul 22, 2022
    your propane detector and any circuit boards in the camper will be drawing power. 1/2 a amp isnt much, but it is why a lot of people used to kill there batteries over the winter when the manufactures started putting parisidic load items into the rv's

    Steve
  • maria_bettina's avatar
    maria_bettina
    Explorer
    Jul 23, 2022
    time2roll wrote:
    1/2%C would be a normal draw when full. 200Ah would be 1 amp. I call full and normal and probably floating.

    Float closer to 13.1-13.3 is plenty in the heat. Does the MPPT have a temp sensor or ambient temp compensation? What is the voltage on the battery terminals?


    It's reading 13.3V at 5pm and 96- degrees. That's per the Renogy unit. My hubby can check at the terminals when he gets home.

    The controller shows temp, but not sure about compensation.

    The battery ad claims a "3% self discharge" rate. They claim 3% per month. Yea, right. That's a 0.2Ah per day discharge. But I am getting ~10 to 12Ah discharge per day. This battery is less than 2 years old.
  • maria_bettina's avatar
    maria_bettina
    Explorer
    Jul 23, 2022
    pianotuna wrote:
    Are the batteries being charged via the solar panels?


    Right now, yes. We are packing for a trip, so we didn't connect to shore power at home since the last trip about a week ago. The truck as been outside since then.
  • maria_bettina's avatar
    maria_bettina
    Explorer
    Jul 23, 2022
    StirCrazy wrote:
    your propane detector and any circuit boards in the camper will be drawing power. 1/2 a amp isnt much, but it is why a lot of people used to kill there batteries over the winter when the manufactures started putting parisidic load items into the rv's

    Steve


    Lwiddis wrote:
    Half an amp isn’t high use IMO. Smoke detector, co2 detector, entertainment center, TV booster etc.



    Only thing drawing power is the Renogy unit. No circuit boards, no detectors. We have a pop-up TC bare bones.
  • maria_bettina's avatar
    maria_bettina
    Explorer
    Jul 23, 2022
    Now that the sun is going down, battery is out of float stage and charging (there is still a wee bit of light) and reads 12.8V and 80% full.
  • time2roll's avatar
    time2roll
    Nomad
    Jul 23, 2022
    80%? Battery is 100% resting at 12.8 volts. Everything seems to be working as expected and ready for an excursion.

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