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jimbok58's avatar
jimbok58
Explorer
Dec 20, 2015

inverter/converter

hi all,
I noticed while plugged into 110 at the house that the inverter was drawing 8-9 amps while charging the house batteries. once the batteries were full, only 1 amp. I never noticed this before. I suppose it normal to draw amps while charging the house batteries?. thanks for any input.
jim
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    I assume you mean the inverter drew 8-9 amps on the AC side of life. Thus making it a MEDIUM (Dang near a BIG) load.

    Mine can hit 11 (Big load) if the batteries are low.

    In fact if you read any of my posts on the limits of 30 amps I mention this.

    Output current is aroudn 800-900 percent of input current.

    So if it's drawing 10 amps from the mains, output can be around 80-90 amps or less depending on the type of charger.. LESS.. Mine hits 11 amps at 80 amps out.

    The math is fairly simple.. Watts = Volts Times Amps (DC) or Volts Times AMps times Power factor (AC) for this we will bundle the power factor with the convwersion loss so Watts = Volts times amps

    Watts in, Times conversion factor (Effiency) = Watts out

    So if you are putting out 100 amps at 12 volts. You need at the very minimum 10 amps input at 120 volts.

    That is simplified, Output is likely 14 volts and change.
  • First off, an inverter does not charge 12VDC. An inverter provides 120VAC from a 12V source.

    You may have an inverter/charger but that is only common on upper end units unless after market installation.

    What you probably have in a converter/charger. The converter changes 120VAC to 12VDC while the charger uses 120VAC to charge the battery bank. What you are seeing on the guage is what the charger is using to charge your battery bank.

    If you do have an inverter/charger that same guage may show your power consumption when on the inverter.
  • thank you sir, i forgot to update my profile, its now a 2015 fleetwwod southwind
    34a. i keep the battery water levels topped off.
  • Old-Biscuit wrote:
    Your 2012 Fleetwood came with a 50A 'converter' which will supply all 12V DC power when connected to shore power/generator AND maintain charge on your house batteries.
  • A converter putting out 60 amps of 12v DC has to get that power from somewhere. The 60 amps of 12v DC calculates to 6 amps of 120v AC, but you have to add some for system losses. I would figure about 7 amps in reality, so your 8 to 9 amps is in the ball park.
  • jimbok58 wrote:
    hi all,
    I noticed while plugged into 110 at the house that the inverter was drawing 8-9 amps while charging the house batteries. once the batteries were full, only 1 amp. I never noticed this before. I suppose it normal to draw amps while charging the house batteries?. thanks for any input.
    jim


    If your RV was left unplugged for say 5 days, then plugged in, the CO meter, propane detector and refrigerator can draw about 1.2 amps per hour 12 VDC, and can run down a set of batteries in 3-6 days.

    When you first plug in the RV, it can draw 5 amps A/C to put out 50 amps DC to recharge the battery. Once the battery is full, then it would be normal to drop back to about 1 amp A/C to charge the battery and keep up with small loads inside the RV on the DC side.

    Yes what you are seeing is normal.

    Have you checked your battery water level lately? Often forgotten, it needs a little distilled water every month or so, but can go 3 months then add a lot of water.. .

    Good luck,

    Fred.
  • Your 2012 Fleetwood came with a 50A 'converter' which will supply all 12V DC power when connected to shore power/generator AND maintain charge on your house batteries.
  • The power to charge the batteries has to come from somewhere so yes, it would draw power from your shore power connection.
    By the way, an inverter changes 12v DC into 120v AC. A converter does the opposite, it changes 120v AC into 12v DC.
    Some units do both, they are called inverter/chargers. These usually only come stock in uper-end motorhomes.
  • That sounds about right for the converter amperage. After batteries are charged in drops down and then you are reading items such as the LP detector, refer control and other light loads.
    Just for information: an INVERTER changes 12 volts DC to 120 volts AC. A Converter changes 120 volts AC to 12 volts DC.
    Odd are you have a converter.

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