Rv Water Heater Amp Draw

So you want to know how many apps your RV or camper appliances draw?

If you don't have time to read the complete article (tsk, tsk), then check out these complete tables!Or click the big blue button to read about them in more depth.

And scroll down for a short n' sweet guide to the inner workings of an RV electrical system. And how to calculate how many amps your RV uses yourself. (Hint: You'll need a watt-meter!)

120V Load RV Amp Draw Table

Appliance	Running Watts, Avg	Amps (@115V)	Notes
Air Conditioner 13.5k BTU, Cooling Mode	1250	10.9	High-efficiency units ~15-25% less power draw. Starting watts 2x!
Air Conditioner 15k BTU, Cooling Mode	1500	13.0	High-efficiency units ~15-25% less power draw. Starting watts 2x!
Window Air Conditioner, 5k BTU	500	4.3	Starting watts 2x!
Absorption Refrigerator, AC Operation	300-575	2.5-5.0	If icemaker, 2x! Starting watts 2x-3x!
6-gallon Water Heater, AC Operation	1400	12.2	~0 AC power used when on LP mode
DC Converter/Charger	0-1500	0-8/13	Based on your 12V loads and battery state of charge! Smaller converters max out 750-100W
Ceramic Space Heater, 1500W	1500	13.0
Oscillating/Box Fan	50-150	0.4-1.3	The smaller and slower the fan, the less power drawn.
Laptop Computer	50-150	0.4-1.3	Gaming, video draws more power.
DVD Player	20-50	0.2-0.4
Smartphone	2-6	0.02-0.05	Your smartphone has more computing power than Apollo 11!
Xbox / Game Console	65-180	0.6-1.6
Hair Dryer	800-1500	7-13
Curling Iron	60-100	0.5-0.9
Coffee Maker, Heating Up	1300-1500	11.3-13.0	Maybe consider a drip cone?
Coffee Maker, Keeping Warm	200-400	1.7-3.5
Toaster (4-Slice)	800-1500	7-13
Food Processor	400-1000	3.5-8.7
Blender	200-1000	1.7-8.7	Low power is harder on the motor!
Induction Cooktop (7-inch)	1200-1800	10.4-15.6
Crock Pot	75/175/250	0.7/1.5/2.2	Warm/Low/High
Microwave 900-1000W	1200-1500	10.4-13.0	At 100% power.
Microwave 1450W (Convection)	1450	12.6	At 100% power.
Microwave 1450W	1450	12.6	At 100% power.
Handheld Vacuum	460-700	4-6
Washer/Dryer	1600-1850	14-16
Electric Heating Blanket	50-225	0.5-2.0
Battery Charger, 15A	1700	15	Output efficiency usually 80-85%
Drill, 5A	575	5.0	Get a cordless drill, you Neanderthal!
Satellite Dish	25-250	0.2-2.2

12V Load RV Amp Draw Table

Load	Watts	Amps @12V	Notes
LED Light	1.9-3.2	0.14-0.25	RECOMMENDED!
Incandescent Light	15-40	1.1-3.0
Fluorescent Light	10-30	0.9-2.0	Not recommended for RVs
Ceiling Fan	20/30/50	1.5/2.2/3.7	Low/Med/High
Furnace 16k BTU (LP Mode)	45-60	3.4-4.3
Furnace 25k BTU	100	7.5
LP/CO2 Detector	2	0.15
Water Pump	50-110	4-8	Only while running
Range Hood	20-40	1.5-3.0
Absorption Fridge, DC Mode	180-275	14-20
Absorption Fridge, LP Mode	15-20	1.5
12 Television	35-50	2.5-3.5
12V Stereo Head	7-50	0.5-3.5	Depends on speaker zone and volume
12V Outlet, Socket	120-130	10	Max charge rate
12V Outlet, USB	25	2.1	Max charge rate
AC/DC RV Fridge	50-180	4-13.5	Varies widely by make and model!
AC/DC Fridge/Freezer, Portable	8-30	0.7-2.3	Incredibly efficient!

Affiliate Disclaimer: Some of the product links are on this page are affiliate links. If you click through and purchase, I may receive a small commission at no extra cost to you. Thanks!

Basics of RV Power Usage

Almost all RVs are powered by either a 30-amp 120-volt* service or 50-amp 240-volt service

A converter then transforms some of the 120-volt electricity to 12-volt electricity. The converter is the heart of your RV's electrical system.

Actually, I pretty much wrote an entire compendium about the humble RV converter here.

You may see this referred to as 110, 115, 120, or even 125 volt service! For our purposes, they all mean the same thing.

Some RVs also have an inverter, which works in the opposite direction: Turning 12-volt DC electricity into 120-volt AC electricity.

Common 240-volt appliances are:

Washer
Dryer
Electric oven

These appliances are typically reserved for luxury fifth-wheels and motorhomes. Again, they require 50-amp, 240-volt hookup in order to function.

Common 12-volt loads are:

Lights
Water pump
12V television
Ceiling fans
Stereo head
Slide-out motors

Many other smaller items, like CO2 detectors and lighted door handles, also run on 12V DC power. This electricity is supplied directly by the house batteries or through the converter.

Other appliances, namely the furnace and refrigerator, are designed to run best when using propane, but several models can switch to AC electric operation when hooked up to campground service.

Some components, such as a 3-way absorption fridge or AC/DC compressor refrigerator, can run strictly off 12V DC power! But be warned: "DC mode" consumes an enormous amount of power in a very short time. It is not practical for most RVers.

If you want to know more (or everything) about RV batteries and how they power RV appliances, check out my ultimate battery guide here.

Also, you should know that many appliances, such as an absorption refrigerator, propane stovetop or furnace, still require some 12V power to operate control electronics, temperature-sensing fans, etc.

How Much Power Do My RV Appliances Use?

*Beware: Math Ahead!*

Before you examine the tables, however, you should understand that amps do not equal power!

This is because of Ohm's Law: Watts = Volts x Amps

W = V*A

Watts measure power. Amps measure current. To supply a steady amount of power, as voltage decreases, amps must increase!

A 1500-watt space heater will consume 1500 watts of power no matter how you run it (theoretically, anyway). Power is power!

At 120 volts, that's 12.5 amps.
At 12 volts, that's 125 amps! Yeesh!

So switching from "shore power" to "battery power" increases amp draw by 10x!

Even though it's not technically accurate, a lot of RVers remember this by distinguishing "DC" amps and "AC" amps.

Here's the rough math: If you need to convert AC to DC amps, multiply by 10. If you need to convert DC amps to AC amps, divide by 10.

For example:

If a 3-speed ceiling fan draws 3.1 amps on High, that's "DC" amps! In other words, it will consume 3.1 amps, per hour, from the 12-volt battery.

However, if you remove the battery from the system, and you run the ceiling fan on converted electricity from the campground power supply, you'd only be consuming 0.31 "AC" amps!*

*Technically, you'd actually be consuming more, because converters aren't 100% efficient, but let's ignore that for now.

Anyway, here's my table for amp draw for 120-volt appliances. You can filter and sort! Make good use of it!

RV Appliance Amp Draw: 120VAC

120V Load RV Amp Draw Table

Appliance	Running Watts, Avg	Amps (@115V)	Notes
Air Conditioner 13.5k BTU, Cooling Mode	1250	10.9	High-efficiency units ~15-25% less power draw. Starting watts 2x!
Air Conditioner 15k BTU, Cooling Mode	1500	13.0	High-efficiency units ~15-25% less power draw. Starting watts 2x!
Window Air Conditioner, 5k BTU	500	4.3	Starting watts 2x!
Absorption Refrigerator, AC Operation	300-575	2.5-5.0	If icemaker, 2x! Starting watts 2x-3x!
6-gallon Water Heater, AC Operation	1400	12.2	~0 AC power used when on LP mode
DC Converter/Charger	0-1500	0-8/13	Based on your 12V loads and battery state of charge! Smaller converters max out 750-100W
Ceramic Space Heater, 1500W	1500	13.0
Oscillating/Box Fan	50-150	0.4-1.3	The smaller and slower the fan, the less power drawn.
Laptop Computer	50-150	0.4-1.3	Gaming, video draws more power.
DVD Player	20-50	0.2-0.4
Smartphone	2-6	0.02-0.05	Your smartphone has more computing power than Apollo 11!
Xbox / Game Console	65-180	0.6-1.6
Hair Dryer	800-1500	7-13
Curling Iron	60-100	0.5-0.9
Coffee Maker, Heating Up	1300-1500	11.3-13.0	Maybe consider a drip cone?
Coffee Maker, Keeping Warm	200-400	1.7-3.5
Toaster (4-Slice)	800-1500	7-13
Food Processor	400-1000	3.5-8.7
Blender	200-1000	1.7-8.7	Low power is harder on the motor!
Induction Cooktop (7-inch)	1200-1800	10.4-15.6
Crock Pot	75/175/250	0.7/1.5/2.2	Warm/Low/High
Microwave 900-1000W	1200-1500	10.4-13.0	At 100% power.
Microwave 1450W (Convection)	1450	12.6	At 100% power.
Microwave 1450W	1450	12.6	At 100% power.
Handheld Vacuum	460-700	4-6
Washer/Dryer	1600-1850	14-16
Electric Heating Blanket	50-225	0.5-2.0
Battery Charger, 15A	1700	15	Output efficiency usually 80-85%
Drill, 5A	575	5.0	Get a cordless drill, you Neanderthal!
Satellite Dish	25-250	0.2-2.2

P.S. Lest you become confused … I calculated the amp draw based on a line voltage of 115V. As a rule, the farther away from the electrical service entrance, the lower your line voltage (due to resistance losses).

In most campgrounds, you won't get the full 120 volts … you'll probably get 110-115.

And remember! As the voltage decreases, the amp draw increases! One balances the other to supply a constant amount of power! So the lower the line voltage, the more likely you are to overload or overheat a circuit. If your surge protector or voltmeter shows less than 108-110 volts at the site plug in, go somewhere else. Be safe!

… wait, you don't have a surge protector? What, do you also run the bulls and BASE jump and try to deep-fry your own turkey? Are you crazy?? Learn about why (and what) you need for a surge protector here.

RV Appliance Amp Draw: 12VDC

12V Load RV Amp Draw Table

Load	Watts	Amps @12V	Notes
LED Light	1.9-3.2	0.14-0.25	RECOMMENDED!
Incandescent Light	15-40	1.1-3.0
Fluorescent Light	10-30	0.9-2.0	Not recommended for RVs
Ceiling Fan	20/30/50	1.5/2.2/3.7	Low/Med/High
Furnace 16k BTU (LP Mode)	45-60	3.4-4.3
Furnace 25k BTU	100	7.5
LP/CO2 Detector	2	0.15
Water Pump	50-110	4-8	Only while running
Range Hood	20-40	1.5-3.0
Absorption Fridge, DC Mode	180-275	14-20
Absorption Fridge, LP Mode	15-20	1.5
12 Television	35-50	2.5-3.5
12V Stereo Head	7-50	0.5-3.5	Depends on speaker zone and volume
12V Outlet, Socket	120-130	10	Max charge rate
12V Outlet, USB	25	2.1	Max charge rate
AC/DC RV Fridge	50-180	4-13.5	Varies widely by make and model!
AC/DC Fridge/Freezer, Portable	8-30	0.7-2.3	Incredibly efficient!

P.S. Again, lest you become even more confused … I calculated the amp draw based on circuit voltage at 13.6. That's above the voltage of fully charged battery, but it's roughly equivalent to the output of a running converter.

In actuality, voltage might drop as low 11.5 volts before you discover your battery is "dead." Amp draw will increase correspondingly.

That's the long way of saying actual amp draw could be 10-20% greater than what's shown here.

How to Actually Measure Your RV Appliance Amp Draw

If you want to know the actual power draw for your particular appliance, you can do two things:

Look at the electrical requirements sticker information on the part, or search for the product listing page online. Most listed appliances will specify the input wattage to the part.

Better yet, measure it yourself. Get a plug n' play watt meter, like this one here, and find out exactly how much power your appliance is using!

Seriously … I cannot recommend this enough. GET A WATT METER! The Kill-A-Watt is my favorite. You can check out the Kill-A-Watt meter here on Amazon.

Here's how this plays out in reality. Most RVers have one of two questions:

How many appliances can I run at one time?
How long can I run my RV off my battery?

Let's consider both questions.

Psst . . . if you're reading this content anywhere besides Ask The RV Engineer, it's been illegally "scraped," and you're probably on a spam website. So please be careful! Don't share any private information, and come back to us at www.askthervengineer.com!

How Many Appliances Can I Run At One Time in My RV Camper?

Usually, at a developed campground, you can either plug into 30A or 50A service.

When hooked up, there is no need to conserve power. The grid won't run out. But if you run too many appliances at one time, you could overload a circuit and trip a breaker!

Some people will tell you that you need to measure or calculate the amp draw of every single one of your appliances and loads.

This is a massive waste of time.

As you can see in my chart, things like laptop computers, LED lights, televisions and oscillating fans simply don't use that much power.

In fact, you really only need to consider three things:

Appliances that make heat
Appliances that cool (aka air conditioners)
Appliances that move stuff (aka, with motors).

Let's call these M3 appliances.

As you can see, electric water heaters, hair dryers, microwaves, electric refrigerators, coffee makers and space heaters all consume A LOT of power!

And while they don't run for long periods of time, electric motors for awning extensions, automatic stabilizers, and slide-outs can demand a huge inrush of current!

So do portable, window and roof mount air conditioners. If you want to learn which RV rooftop air conditioners are the most energy-efficient, click here.

Here are three useful rules of thumb:

Assume you can only run one (1) M3 appliance per circuit.
Assume you can only run two to three (2-3) M3 appliances on 30A power and three to four (3-4) on 50A power.
If you're running a generator, assume you can run one (1) 2M appliance per 1500-2000 running watts.*

… and here's my last caveat. M3 appliances with a motor – such as a fridge, A/C, or slide-out motor – often demand lots of energy upon startup (often 2-3x their running watts).

We engineers call these "inductive" loads rather than "resistance" loads.

Therefore, the startup demands of an air conditioner can easily overload a circuit. This is one reason I recommend a soft-start for your RV A/C!

How to Fix an Overloaded Circuit

All your 120-volt circuits run through your main breaker panel, probably located inside your converter/charger/power center.

These circuit breaker switches will flip when overloaded. Just flip the breaker switch to reset the circuit.

However, usually, the 12-volt circuits are protected with fuses, not circuit breakers. If a 12-volt circuit is overloaded, the fuse will blow. You'll need to replace the fuse with the same size and type. Some converters have LED indicator lights to indicate which fuse is ruined.

How Long Can I Run My RV Off Battery?