In this article, I discuss the Amp draw, Power Usage (Watts), and Energy Consumption (kWh) of 13500 BTU RV air conditioners.
Whether you’re looking to size equipment, such as solar panels, batteries, an inverter, or a generator, this article will provide all the information and estimates that you need.
Let’s get started.
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How many Amps does a 13500 BTU RV air conditioner use?
Typically, 13500 BTU RV air conditioners use around 13 to 17 Amps, depending on the specific model. The main component of the unit, the compressor, draws approximately 10 to 13 Amps. At the same time, the fan consumes about 2 to 3.5 Amps when running at its highest speed.
The exact amp draw of these air conditioners will mainly depend on the model and its efficiency.
For an accurate determination of the amperage for your 13500 BTU air conditioner, you should refer to the manufacturer’s specifications. These electrical details are usually available on a nameplate attached to the air conditioner, located on the roof of your RV.
On the nameplate, the manufacturer will usually specify the amp draw of the different components of the air conditioner. For example, let’s take a look at this nameplate attached to a 13500 BTU RV air conditioner:
On the nameplate, the manufacturer specifies 4 Amperage ratings:
- Compressor LRA
- Compressor RLA
- Fan Motor FLA
- Optional Electric Heater Amps
Compressor LRA:
LRA, which stands for Locked Rotor Amps, indicates the potential “inrush” current (in Amps) that the compressor may need to start up.
Although the manufacturer specifies an LRA of 63 Amps, the compressor usually doesn’t always require the full 63 Amps to start up. Instead, the actual starting amps typically fall within the range of 25 to 35 Amps for a 13500 BTU RV air conditioner.
However, it’s still important to take this LRA rating into account when sizing equipment. (More on that below)
Compressor RLA:
RLA stands for Running (or Rated) Load Amps, and it represents the amount of current that the air conditioner uses when it’s up and running.
For this particular model, the manufacturer specified an RLA of 12.2 Amps.
Fan Motor FLA:
FLA stands for Full Load Amps, and in this case, it represents the amount of current drawn by the motor that drives the condenser and blower fans when it’s operating at full speed. For this air conditioner, the fan motor is rated at 3.4 Amps of current.
Optional Electric Heater Amps:
The electric heating element of this air conditioner has an amperage rating of 13.2 Amps.
Now, how many amps will this 13500 BTU RV air conditioner use when it’s running?
In cooling mode, the 2 main components that’ll be drawing current are the compressor and the fan motor. Therefore, the total amp draw of the air conditioner in cooling mode is calculated as follows:
Total Amp Draw (Amps) = Compressor RLA (Amps) + Fan Motor FLA (Amps)
Total Amp Draw (Amps) = 12.2 Amps + 3.4 Amps
Total Amp Draw (Amps) = 15.6 Amps
In heating mode, the two components that’ll be drawing current are the heating element, which is rated at 13.2 Amps, and the fan motor (3.4 Amps). The total amp draw of the air conditioner in heating mode is:
Total Amp Draw (Amps) = Electric Heater Amps (Amps) + Fan Motor FLA (Amps)
Total Amp Draw (Amps) = 13.2 Amps + 3.4 Amps
Total Amp Draw (Amps) = 16.6 Amps
Now that we have an idea of the amp draw of 13500 BTU air conditioners, let’s examine their power usage, measured in Watts.
How many Watts does a 13500 BTU RV air conditioner use?
A 13500 BTU RV air conditioner will typically use between 1300 and 1800 Watts of power, which equates to 1.3 – 1.8 kW (kiloWatts). The compressor alone will typically draw between 1100 and 1400 Watts, and the fan motor will draw up to 400 Watts when operating at full speed.
To calculate the power usage of your RV air conditioner in Watts using the Amp draw of the unit and its Voltage, both of which are provided on the nameplate:
Power usage (Watts) = Voltage (Volts) x Total Amp Draw (Amps)
For instance, based on the Amperage ratings provided in the nameplate from our previous example, we have calculated that the amp draw of the 13500 BTU air conditioner is 15.6 Amps.
Also, on the nameplate, it states that the “A/C Voltage” is 115 Volts, which is a common voltage for appliances in the U.S.
Using these ratings (Voltage and Amperage), we can calculate the rated power usage of the air conditioner as follows:
Power usage (Watts) = Voltage (Volts) x Total Amp Draw (Amps)
Power usage (Watts) = 115 Volts x 15.6 Amps
Power usage (Watts) = 1794 Watts
What we’ve just calculated is the running wattage of the air conditioner in cooling mode. To find the running wattage of the AC in heating mode, we can use the same formula but this time, with the amp draw when the electric heater and the fan are running (16.6 Amps):
Power usage (Watts) = Voltage (Volts) x Total Amp Draw (Amps)
Power usage (Watts) = 115 Volts x 16.6 Amps
Power usage (Watts) = 1909 Watts
Now, according to our calculations, the 13500 BTU RV air conditioner can draw as much as 1794 Watts when it’s producing cool air, and up to 1909 Watts when it’s producing warm air.
However, in both cases, we’ve only calculated the “Running” wattage of the air conditioner. When sizing equipment that’ll run your air conditioner, such as an inverter or a generator, both the running and starting wattage of the AC need to be considered.
So, how many watts does a 13500 BTU use when it’s starting up?
A 13500 BTU RV air conditioner will usually use approximately 3000-4000 Watts for a brief moment when you turn it on. However, in certain instances, the starting wattage of these air conditioners can reach up to 8000 Watts.
To calculate the potential starting wattage of the air conditioner, you can use the Compressor LRA and the Fan Motor FLA ratings we discussed earlier.
For example, let’s say a 13500 BTU air conditioner has an LRA rating of 63 Amps and an FLA of 3.4 Amps. At 115 Volts, the potential starting wattage of the air conditioner is:
Potential Starting Wattage (Watts) = (Compressor LRA (Amps) + Fan Motor FLA (Amps)) x Voltage (Volts)
Potential Starting Wattage (Watts) = (63 Amps + 3.4 Amps) x 115 Volts
Potential Starting Wattage (Watts) = 66.4 Amps x 115 Volts
Potential Starting Wattage (Watts) = 7636 Watts
As mentioned earlier, the air conditioner won’t necessarily require the full 7636 Watts of power when turned on; it usually needs only 3000 – 4000 Watts.
However, if we were planning on running this AC on an inverter, it would be advisable to choose an inverter with a Peak (Surge) Power rating higher than 7636 Watts. This precaution will help avoid any potential issues with starting the air conditioner in the future.
Click here to learn more about sizing an inverter for your RV air conditioner.
For example, the following inverters are all rated at 4000 Watts of “Continuous” power, and 8000 Watts of Peak/Surge power:
The same principle also applies to generators if you intend to run your RV AC on one. However, unlike inverters, which usually have a Peak Wattage rating that is double or even triple their Running Wattage, generators can only manage a surge wattage that is 110% to 125% of their running wattage.
Let’s consider the DuroStar DS4000S generator as an example, which has a continuous power rating of 3300 Watts and a maximum starting wattage of 4000 Watts.
In general, this 3300W generator should be capable of running a 13500 BTU RV air conditioner. However, if for any reason the starting wattage of the air conditioner does increase to 7636 Watts, the generator will be unable to start the AC.
A more reliable choice would be the DuroMax XP8500EH, with a running wattage of 7000 Watts and a starting wattage capacity of 8500 Watts.
This generator can not only start and run your RV air conditioner but also power multiple other appliances simultaneously, as long as your RV’s electrical system can handle the load.
Learn how to size a generator for your 13500 BTU RV AC here.
Another option is to install a Soft starter device on your RV air conditioner. Devices such as the SoftStartRV or the MicroAir Easystart 364 can be used to limit the initial inrush current to about 20 amps, and the starting wattage of the AC to about 2500 Watts.
Now that we’ve covered Amp draw and Power usage, let’s discuss an even more important aspect of the electricity usage of 13500 BTU air conditioners.
How much Energy (kWh) does a 13500 BTU RV air conditioner use?
The actual energy consumption of an RV air conditioner depends on several factors like outdoor temperature, indoor temperature setpoint, shading, insulation quality, and the age and efficiency of the air conditioner.
However, as a rough estimate, a 13500 BTU RV air conditioner typically uses around 1 to 1.2 kWh (1000 to 1200 Watt-hours) of energy per hour of operation. If you assume 8 hours of daily usage, the daily energy consumption would be approximately 8 to 9.5 kWh.
Since energy (kWh) represents the actual amount of electricity that an appliance consumes over a certain timeframe, the exact energy consumption of your RV’s air conditioner becomes the most important metric if you’re planning on running the air conditioner on solar panels or batteries.
Conveniently, you can estimate the energy consumption using the Running Wattage (Watts) of your air conditioner. The following rule of thumb can be used:
Energy Consumption (kWh) = (Running Wattage (Watts) x Usage Duration (hours) x 0.8) ÷ 1000
For example, let’s say your 13500 BTU AC has a Running Wattage rating of about 1400 Watts. Let’s also make the assumption that you typically run the air conditioner for 4 hours a day.
The estimated daily energy consumption of the air conditioner is:
Daily Energy Consumption (kWh/day) = (Running Wattage (Watts) x Daily Usage Duration (hours/day) x 0.8) ÷ 1000
Daily Energy Consumption (kWh/day) = (1400 Watts x 4 hours/day x 0.8) ÷ 1000
Daily Energy Consumption (kWh/day) = (4480 Watt-hours/day) ÷ 1000
Daily Energy Consumption (kWh/day) = 4.48 kWh/day
If, for example, we wanted to get a battery bank that is able to run the air conditioner for a day if required, the battery bank will have to have a Usable Energy Capacity of at least 4.48 kWh.
A good example of this would be to use 2 of the LiTime 12V-200Ah Lithium batteries, which would give us 4.8 kWh of usable battery capacity.
Related: How many batteries to run your RV air conditioner?
If we wanted enough solar power to run the AC, the solar panels would have to be able to generate 4.48 kWh of energy or more on a daily basis. As I explain in this article, the size of the solar array would depend on the amount of sunlight that’ll be available to the solar panels, a.k.a. Peak Sun Hours.
However, if we assume 5 Peak Sun Hours a day, the system would have to be rated at 896 Watts or more (4480 Wh ÷ 5 Peak Sun Hours = 896 Watts).
A good example of this would be 5 of the Renogy 200 Watt solar panels, which would make up a 1000 Watt (1 kW) solar system.
