Generator/Battery Power Estimation

[bnimtz]

Has anyone figured out a good rule of thumb or found a good guide on trying to estimate what the power consumption is of the NoBo electric items?

Have the solar package (1 panel on top), two regular deep cycle batteries, 12V Fridge, microwave oven, A/C.

2022 NoBo 19.8. Mainly looking for what generator size needed to reliability run 12V fridge and either A/C or furnace (propane). Along with misc lights and maybe a fan, radio, phone charger. Furnace controls and water tank heaters would come into play in the fall. I guess I’m not sure if the water tank heaters are electric or propane. Looking at an inverter generator like the Hondas or Generacs.

Thank you

[Boomerweps]

Originally Posted by bnimtz

Has anyone figured out a good rule of thumb or found a good guide on trying to estimate what the power consumption is of the NoBo electric items?

Have the solar package (1 panel on top), two regular deep cycle batteries, 12V Fridge, microwave oven, A/C.

2022 NoBo 19.8. Mainly looking for what generator size needed to reliability run 12V fridge and either A/C or furnace (propane). Along with misc lights and maybe a fan, radio, phone charger. Furnace controls and water tank heaters would come into play in the fall. I guess I’m not sure if the water tank heaters are electric or propane. Looking at an inverter generator like the Hondas or Generacs.

Thank you

First, you need to regroup.
The purpose of solar is to recharge batteries. It doesn’t power much on its own.
Many TT systems use 12vdc as control power even though they use propane as a heat source, furnace, propane fridge (not applicable for you), water heater.
Water heaters can be tricky. My Suburban water heater has an AC electric element but the power switch for electric is hidden under piping on the exterior.
Air conditioning uses a massive amount of power, even on small TT, pushing 15 amps. So if you want Air Conditioning, you’ll need either a massive battery bank and inverter, or a 3000 watt or so generator or the Honda 2200 watt inverter generator WITH a Soft Start module (~$240) installed in your Air Conditioner.
Best way I found to determine power use for AC current was to use a plug in Kill-A-Watt meter (available at Harbor Freight) and turn items on and off. I did have to use some adapters to be able to plug it in line on the TT power inlet jack. Readings in volts, watts & amps.
MY air conditioner, while running, uses 12.05 amps. I couldn’t see the startup reading since I started it inside and had to go outside to read the meter. I have since added the soft start but haven’t remeasured. I need to do that. I’m hoping my 2000 watt Honda will support the AC. Regardless, it will be tight power management, a pick one kind of thing, microwave (10.25 amps), water heater (10.38 amps), portable electric heater (12.5 amps), AC (12.05 amps), single serve coffee maker (6.67 amps). Basically anything with a motor or heating element.
I strongly believe that your current solar power system was designed to mostly support having an operating 12vdc fridge.
IIRC, wattage divided by voltage equals amperage. And conversely, amps times volts equals watts. Read the item label plate for power usage and do the math to figure power usage in the terms you need since most generators are wattage rated. Forget peak ratings except for motor startups. So my Air Conditioner uses 1446 watts at 120VAC while running.

[Aussieguy]

your 9.8 would probably have a 30 amp power cord to the pedestal
30amps X 120v = 3600watts generator is the largest you need.


now you can downsize a bit
by deciding what appliances you will run at the same time.
air conditioner will need around 2500w and a soft start may be required

the smaller you go in generators ..... the harder they have to work
which means they get louder.



I have 2 generators and take along the one that suits me at the time of year
3500w Champion to run a/c and all other stuff .... it barely gets above idle speed and is pretty quiet


Older Honda i2000w when no a/c is required
charge batteries etc


Running a travel trailer / RV is all about power management

[bnimtz]

Thank you both. I’ve camped at most with a 40yr old pop up or out of the back of my truck/tent, so never really having to worry about all these appliances. Got this camper with intention to use a few times during summer as I’ve previously camped, but also several times in Sept/Oct in northern MI for hunting.

There will be some feeling out and ultimately we’re camping, so A/C and microwave arn’t critical. Properly won’t use water too much unless at a full hookup site. I’m mostly concerned about fridge and then heat in fall. Also don’t know how the single solar package panel will perform. Would be great if solar could provide power for fridge and mindful usage of phone charging/lights/small fan. Not super experienced with solar so I’m skeptical until I test it out.

My thinking was either two of the smaller 2200W inverters generators and parallel them if needed or one single ~3500W inverter generator. I did realize the 120V x 30A = 3600W limit here this morning too, so anything over that is unable to be used.

[Chuck_S]

Email me for my old "Roo Amps" spreadsheet if you want. I measured all the 12vDC draws (to 0.01amp) when determining the batteries (plural) I needed if shorepower was not available. No 12v or inverter-refrigerator (thankfully!) and I recently replaced all the ceiling lights with LEDS. 16 hours of flame time on the furnace will kill a common Group 24 battery for example leaving just enough power for some dim lights.

-- Chuck