What Size Generator do I need for my Motorhome?

To calculate the generator size you need to run a UK motorhome without air conditioning, you can follow a similar process as before, but this time we'll exclude the air conditioner from the calculations. Let's work through a practical example:

Appliances: LED lights, refrigerator, microwave/coffee machine, TV, and laptop.

Wattage ratings:

LED lights: 10W

Refrigerator: 150W

Microwave (starting surge): 1,000W/1500W

TV: 50W

Laptop: 50W

Step 1: List your appliances and wattage ratings.

LED lights: 10W

Refrigerator: 150W

Microwave (starting surge): 1,000W/1,500W

TV: 50W

Laptop: 50W

 

Step 2: Calculate the total power requirement.

Total power requirement = LED lights + Refrigerator + Microwave + TV + Laptop

Total power requirement = 10W + 150W + 1,000W /1,500W + 50W + 50W

Total power requirement = 1,260W/1,760W (or 30 kW)

Step 3: Add a safety margin.

Add a safety margin of 20% to the total power requirement:

Safety margin = 0.2 x Total power requirement

Safety margin = 0.2 x 300W

Safety margin = 300W (or 0.3 kW)

Step 4: Calculate the generator size.

Generator size = Total power requirement + Safety margin

Generator size = 3.0 kW + 0.3 kW

Generator size = 3.0 kW

Maxpeedingrods MXR3500 Pure Sine wave Inverter Generator

For this example, you would need a generator with a capacity of approximately 3 kW. As mentioned previously, you may choose to round up to the nearest available generator size, such as 3.5 kW or higher, for added flexibility and to ensure you have sufficient power for your motorhome's electrical needs.

Remember to verify the wattage ratings of your specific appliances and consider factors like generator type, fuel source, and noise level when selecting the right generator for your motorhome. Also this is calculated with all appliances running at the same time, in reality this would not happen.