Forum Discussion

Plumber101010's avatar
Plumber101010
Explorer
Jan 29, 2015

Amp Question, Watts, Electrical system.

1) When plugged in, does ANYTHNG run purely off battery power still or only electric converted to 12 volt. Wondering after reading if I am overcharging my batteries by not using them for anything.

2) With 2 Honda 2000 watt generators going. And by the math I learned here, 30 amps x 120 or 115 or 110 (still confused about which it is, it seems to vary in google) is 3600 watts, does the extra 400 watts go anywhere in helping me to run the plug in heaters, or no because the breakers and wring are still going to pop regardless of how much juice I have coming in over 3600 watts / 30 amps? If 30 amps is 3600 watts and I have 4000 watts, is the extra watts lost?

3) Regarding tripping breakers when running couple heater fans, Assuming at LEAST I can plug an extension cord into one of the Hondas 120 outlet in addition to the 30 amp plug and get it that way?

Thanks everyone

10 Replies

  • larry_cad's avatar
    larry_cad
    Explorer II
    Jan 30, 2015
    Watts and horsepower are similar. You can drive a car with a 400 hp motor and if you drive slowly, the motor puts out only 100 hp. Same with your generator. If the load you plug into the generator requires less than the max rating of the generator, the generator will not produce the watts. Oh, and you will accordingly use less gasoline. The watts won't be wasted because they will not be made........from the gasoline.
  • time2roll's avatar
    time2roll
    Nomad
    Jan 29, 2015
    Plumber101010 wrote:
    3) Regarding tripping breakers when running couple heater fans, Assuming at LEAST I can plug an extension cord into one of the Hondas 120 outlet in addition to the 30 amp plug and get it that way?
    Yes you can still use the regular outlets on the generator. The cord needs to be #12 wire if powering an electric heater.

    But you are far better to run the furnace and use propane.

    You can use the convenience outlets in the RV. But just like at home... if you put two heaters on one breaker it will trip.
  • time2roll's avatar
    time2roll
    Nomad
    Jan 29, 2015
    Plumber101010 wrote:
    2) With 2 Honda 2000 watt generators going. And by the math I learned here, 30 amps x 120 or 115 or 110 (still confused about which it is, it seems to vary in google) is 3600 watts, does the extra 400 watts go anywhere in helping me to run the plug in heaters, or no because the breakers and wring are still going to pop regardless of how much juice I have coming in over 3600 watts / 30 amps? If 30 amps is 3600 watts and I have 4000 watts, is the extra watts lost?
    The Hondas only produce what the RV calls for. The extra 400w can still be used for surge performance such as starting the air conditioner compressor. The breaker will not instantly trip with a very short overload same as when you are plugged in.
  • time2roll's avatar
    time2roll
    Nomad
    Jan 29, 2015
    Plumber101010 wrote:
    1) When plugged in, does ANYTHNG run purely off battery power still or only electric converted to 12 volt. Wondering after reading if I am overcharging my batteries by not using them for anything.
    Lead-acid batteries like to be at 100% for long life. OK to give them some exercise once and a while too just to verify they will still work as expected if you need them. Just don't plug in until late the second day and see how it goes.
  • naturist's avatar
    naturist
    Nomad II
    Jan 29, 2015
    Shore power is talked about as 110, 115, or 120 volt because it varies from location to location depending on how close to the power company's transformer you are and what other load might be on that circuit. If you stick a volt meter on it, and watch if for a few days, you will likely see voltages all over that range.

    As far as #3, the answer is no. You can't get more out of the generator than it is capable of producing. As others have noted, you can't get 30 amps out of those two Hondas for more than a couple seconds, which is their surge capacity. After a couple seconds they will either yield a max of 26 amps or they'll kick offline as overloaded.
  • pianotuna's avatar
    pianotuna
    Nomad III
    Jan 29, 2015
    Not usually, however sometimes folks wire in (large) stand alone inverters with dedicated outlets. Those run off the battery bank and converter. If the load is large enough they will draw energy directly from the battery bank. I found that convenient when I was in situations where there was only a 15 amp outlet.

    If you have a modern converter, it will not usually overcharge the battery bank.

    Plumber101010 wrote:
    1) When plugged in, does ANYTHNG run purely off battery power still or only electric converted to 12 volt. Wondering after reading if I am overcharging my batteries by not using them for anything.


    The most you will get continuous is 26.6 amps or 3192 VA which is not quite the same as 3192 watts. I added a hybrid inverter to take care of loads larger than my Yamaha 3000 sIEB can handle.

    Generator makers most often list the surge VA rating so the Honda 2000 is not the continuous load which is approximately 1600 va.

    Plumber101010 wrote:

    2) With 2 Honda 2000 watt generators going. And by the math I learned here, 30 amps x 120 or 115 or 110 (still confused about which it is, it seems to vary in google) is 3600 watts, does the extra 400 watts go anywhere in helping me to run the plug in heaters, or no because the breakers and wring are still going to pop regardless of how much juice I have coming in over 3600 watts / 30 amps? If 30 amps is 3600 watts and I have 4000 watts, is the extra watts lost?


    Find a different circuit inside the RV. Consider replacing the outlets that will be used for heaters, or run the heaters on lower settings.

    Plumber101010 wrote:
    3) Regarding tripping breakers when running couple heater fans, Assuming at LEAST I can plug an extension cord into one of the Hondas 120 outlet in addition to the 30 amp plug and get it that way?
  • westend's avatar
    westend
    Explorer
    Jan 29, 2015
    Plumber101010 wrote:
    1) When plugged in, does ANYTHNG run purely off battery power still or only electric converted to 12 volt. Wondering after reading if I am overcharging my batteries by not using them for anything.No, your converter only applies the necessary charge to maintain the batteries at a full charge state, once charged. Variables on this include the fact that the 12V system is always interacting with the converter's output, the type or make of converter you have, and the health of your batteries.

    2) With 2 Honda 2000 watt generators going. And by the math I learned here, 30 amps x 120 or 115 or 110 (still confused about which it is, it seems to vary in google) is 3600 watts, does the extra 400 watts go anywhere in helping me to run the plug in heaters, or no because the breakers and wring are still going to pop regardless of how much juice I have coming in over 3600 watts / 30 amps? If 30 amps is 3600 watts and I have 4000 watts, is the extra watts lost? Power consumption measured in amps is a measurement of power DRAWN from the power source through the resistance of the wire, switches, and the device being powered. You could have 10 generators capable of 16.6 amps and the power drawn would still only total the resistance of the heaters and wire mentioned above. Circuit breakers are set to trip at a slightly higher power set point than the rating. Continual tripping of a circuit breaker will lower the set point and eventually, lead to the circuit breaker not functioning.
    The assumed power difference delivered (400W) is not "lost" because it is not DRAWN from the power source.

    3) Regarding tripping breakers when running couple heater fans, Assuming at LEAST I can plug an extension cord into one of the Hondas 120 outlet in addition to the 30 amp plug and get it that way? The generator will be limited by the total power DRAWN by the heaters and wiring. Just changing the connection point will not allow the generator a greater power output (except for any difference in the resistance in the different wiring configurations,i.e. extension cord vs. shore power circuit).

    Thanks everyone
  • azrving's avatar
    azrving
    Explorer
    Jan 29, 2015
    These appear to be the numbers for your Honda.

    120V 2000W max. (16.7A) 1600W rated (13.3A)

    So running load is 3200 and 400 is surge.

    Normally it's called 120 but I see voltages of 116 to 125. So yes you basically have 120x13.3x2= 3192 running watts. After that the Honda is ready to trip. Maybe not instantly, maybe it will keep going at 3400 or 3800. I have never tried it. It will surge to 4000 but not remain loaded at 4000. Load/resistance is heat so it's probably best to not run near max load all the time.

    If a product will do it and live long it will probably be a Honda or Yammie. Now that I think of it I have run my Honda 3000 at about max load of 3000 for a short time and it didn't trip. It was while I was running my 55 amp converter and 50 amp battery charger. Again, it was start up and it tapered off rather quickly. I dont do that with it any more though as I'm not into trying to break my sweet Honda.

    If you are trying to run two 1500 watt heaters you should be ok but it would depend on the converter draw. If convert draw is low while in float charge it may be ok, or you may need to shut it off. If they are 1,200 watt heaters (2400) you obviously have more reserve.
  • 2oldman's avatar
    2oldman
    Explorer II
    Jan 29, 2015
    First of all, you're not going to get 30a from that 30a socket. It just means your 30a plug fits in there. If you look on the plate on the hookup side of the Honda, it should say 13.3a continuous. That's the most that generator is designed to handle for 'normal' use. And even then it will be working very hard, and be loud. So, two hooked together are good for 26.6, or about 3,000 watts. Again, that's MAX. The 2,000 watt rating is legally what they can say and get away with it, because it's possible it can surge to that amount for a short time.

    These generators put out a varying amount of power depending on what you're asking for, if I understand you correctly. It's not 4,000 watts all the time.
  • enblethen's avatar
    enblethen
    Nomad
    Jan 29, 2015
    The batteries normally would be out of the system except for charging when connected to shore power. Systems like slides and jacks are connected straight to the batteries due to the heavy loads by many. Operating them would pull battery down as the converter is not normally large enough to operate them.
    Honda gensets have a surge rating of 2000 watts but continuous duty is only 1600 watts each. Calculations should be done using 120 volts.
    No your loading could burn up your gensets or at least the circuit breaker on the gensets should trip. Many heaters are rated near 1500 watts each. Running two along with other devices can overload the circuit. You need to read the wattage or amps of each device total them up. This should be only about 80% of the connected load.
    You must remember that the converter is drawing power all the time to charge batteries and run 12 volt systems. The 120 volt is also using parasitic type loads like microwave clocks.

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