Electrical Usage - Montana Owners Club

OldVol · 01-04-2021, 01:23 PM

First time RV owner with 2019 Montana 3700bk. RV is winterized but still hooked to shore power. Everything is turned off except 18cf fridge and 3 off/on indicator lights. Solar panel charging battery. RV is still using 250 to 300kw per month. Is that usage normal?

Love the rv.

rohrmann · 01-04-2021, 01:41 PM

I would think if the rig is plugged in to shore power, the solar system is being bypassed, so all your load would be from the utility, not solar. With it plugged in, maybe if you were to have a power outage, the solar would take over.

CADman_KS · 01-04-2021, 01:50 PM

Found online that a typical fridge uses about 1040 watts per day. You're using 1250 per day, at 300Kw monthly usage. I'd say, sounds about right...

DutchmenSport · 01-04-2021, 02:11 PM

If you are plugged into shore power, your converter is drawing power. If any appliance is plugged in, even though you have it turned off, they still draw power.

You can turn your battery cut-off, off. You can also turn your inverter, off, if you have one. Turn off the kill switch between the battery and your inverter too, if you have one.

Anything plugged in will have some parasitic draw on your AC power. Unless you disconnect your batteries from the battery terminals, there are still some things that will still be powered, like your CO2 detector.

Something is still plugged in to AC electric. And if you are plugged into your shore power, more than likely, the converter is charging the battery, not the solar system.

mhs4771 · 01-04-2021, 03:10 PM

Deleted

CADman_KS · 01-04-2021, 03:46 PM

Quote:

Originally Posted by mhs4771

All I can say is that we're using approx 400KWH per month Living in our unit here is Florida.

That's not the same as 300Kw...

CADman_KS · 01-04-2021, 03:49 PM

Quote:

Originally Posted by DutchmenSport

If you are plugged into shore power, your converter is drawing power. If any appliance is plugged in, even though you have it turned off, they still draw power.

You can turn your battery cut-off, off. You can also turn your inverter, off, if you have one. Turn off the kill switch between the battery and your inverter too, if you have one.

Anything plugged in will have some parasitic draw on your AC power. Unless you disconnect your batteries from the battery terminals, there are still some things that will still be powered, like your CO2 detector.

Something is still plugged in to AC electric. And if you are plugged into your shore power, more than likely, the converter is charging the battery, not the solar system.

I don't have a solar system to test out, but I would think that if you killed the breaker that powers your converter, you could leave the battery cut-off switch engaged, leave the batteries hooked up, and still be charging your batteries. I have to kill my converter all the time when we are on 30A shore power, or we blow the main breaker outside...

OldVol · 01-04-2021, 03:50 PM

Many thanks to all. Very, very helpful.

Dave W · 01-05-2021, 04:44 AM

My question would be why leave that fridge running - it is a big power user. These, unless it's a residential fridge are not very efficient, using electric heating elements and convection to work. You have winterized the trailer so finish off the job. Of course if you are using that fridge as a supplement to the home unit, then you will just have to expect the higher electric bill.

OldVol · 01-05-2021, 01:25 PM

Food for thought: Talked with the electric company today and discovered some interesting information. My usage has fluctuated from a low of 2kwh a day to a high of 13kwh/day. Highest usage always occurs from midnight to 3:00am. Inverters do draw measurable amounts of current. I suspect that the solar panel charges the battery during the day and the inverter charges it at night. Will have to investigate that theory.

bcrvman · 01-10-2021, 03:07 PM

Quote:

Originally Posted by OldVol

First time RV owner with 2019 Montana 3700bk. RV is winterized but still hooked to shore power. Everything is turned off except 18cf fridge and 3 off/on indicator lights. Solar panel charging battery. RV is still using 250 to 300kw per month. Is that usage normal?

Love the rv.

Seems high. You probably have the same fridge as me, it uses 1.5kWh per day or 45kWh per month. Check the label inside fridge right side, if it is like mine the max amps is 3. Very different from the 12A old style fridges had before the modern Digital Inverter fridge. That still leaves 200 to 250 kWh unaccounted for. If you have a Progressive Industries EMS you can see the amps on the little remote display, if you have a Hughes Power Do the bluetooth app will show the real time power usage broken down by phase. If you have none of those, how comfy do you feel unscrewing the main power panel and putting a clamp on ammeter on each leg? Once you can tell how much current is flowing in each leg, start turning off breakers until you identify which circuit is the culprit. Maybe you forget that you have something plugged into an outside plug, like an electrical space heater to keep the basement warm? Your missing power looks like a 300W small space heater.

OldVol · 01-10-2021, 03:25 PM

Not electrically savvy. There is an app called MY Usage that will give me the total usage by day but doesn't identify how it is used. Many thanks for the info. I will check inside the fridge.

bcrvman · 01-10-2021, 03:42 PM

Quote:

Originally Posted by OldVol

Not electrically savvy. There is an app called MY Usage that will give me the total usage by day but doesn't identify how it is used. Many thanks for the info. I will check inside the fridge.

If you are positive you have nothing else plugged in, then just turn off all the circuit breakers except for the fridge. Why is fridge left on anyway?

bcrvman · 01-10-2021, 03:45 PM

Quote:

Originally Posted by OldVol

First time RV owner with 2019 Montana 3700bk. RV is winterized but still hooked to shore power. Everything is turned off except 18cf fridge and 3 off/on indicator lights. Solar panel charging battery. RV is still using 250 to 300kw per month. Is that usage normal?

Love the rv.

When you say solar panel charging battery, do you mean the solar panel goes to a solar charge controller (probably MPPT) then to the batteries? OR do you have some kind of combination inverter/charger like a Magnum or Victron? NOT counting the fridge inverter. Is this an addon solar system or the factory POS?

DanC · 01-10-2021, 03:48 PM

Quote:

Originally Posted by OldVol

First time RV owner with 2019 Montana 3700bk. RV is winterized but still hooked to shore power. Everything is turned off except 18cf fridge and 3 off/on indicator lights. Solar panel charging battery. RV is still using 250 to 300kw per month. Is that usage normal?

Love the rv.

Several items in your RV draws power...the carbon monoxide detector constantly draws, and the uhf antenna, as well as the hydraulic pump if your equipped. I had power drainage on my Montana and had the dealer check it out and this is what they told me. This was a surprise to them as well. My fridge is off during storage....the only way I can stop these from using power was to install a battery disconnect or remove the batteries. I don't have mine plugged into shore power, but imagine these still draw power.

jrsemrad · 01-10-2021, 07:27 PM

There exists a handy dandy item called Kill A Watt. It can be plugged into a 120v outlet and you can determine the amps, and watts being drawn by anything plugged into it. It also has a recording feature to determine kilowatts over a period of time. I have used adapters on my shore power cable to determine current draw of electrical items in the RV. Some things like the fireplace have a small current draw all the time unless the breaker is off. Try it, you will like it. I used the Kill A Watt to figure out that an old refrigerator of mine was an electrical hog.

OldVol · 01-11-2021, 10:05 AM

Fridge is on because I was too lazy to empty contents and defrost. Learning experience.

OldVol · 01-11-2021, 10:06 AM

No idea what any of that is. Thanks anyway.

DutchmenSport · 01-11-2021, 10:59 AM

Pull the negative cable off the battery. Unplug shore power. Everything is now off. Guaranteed.

chenevb · 01-11-2021, 01:21 PM

Quote:

Originally Posted by OldVol

Fridge is on because I was too lazy to empty contents and defrost. Learning experience.

To add a factual bit of humor here, our RV is winterized and unheated, but we leave it connected because we use the RV resi refrigerator as our second refrigerator. We had a cold streak, and spoiled some veggies in the fridge because they froze. This was a reminder that over time, everything eventually attains ambient temperature, so the refrigerator part can become a freezer too...

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