What Can You Run on a 3000-Watt Inverter in Your RV?

What can you run on a 3000-Watt Inverter in your RV? There are two aspects to this question: how much power is needed at any given time and what is the cumulative total of this work over time, aka energy. Power and energy are words that we use commonly in everyday speech, even if we’re not quite sure what the difference is. It helps to illustrate the differences using some examples. But first, let’s make some assumptions:

• We’re using a 24V lithium house battery bank consisting of two Epoch 24V 230Ah Elite V2 batteries
• Our lithium batteries have a resting voltage of 25.6V when fully charged
• We’ll only discharge our batteries to 10% state-of-charge (SoC)
• We’re using a Victron Energy 3000VA inverter that can output 2400W at 75° and less when the inverter is warmer
• We have 1000W of peak solar capacity on the roof of our RV
• We’re vacationing at the beginning of July in a very sunny location
• Our electrical loads consist of:
  • Rooftop air conditioner consumes 1250W and runs 8 hours per day
  • Microwave consumes 1200W and runs 10 minutes (0.17 hours) per day
  • Hair dryer consumes 1200W and runs 5 minutes (0.08 hours) per day
  • Coffee maker consumes 1400W and runs 5 minutes (0.08 hours) per day
  • Starlink consumes 35W and runs 24 hours per day
  • Floor fan consumes 75W and runs 4 hours per day

Now, we don’t want to always discharge our batteries to completely empty because this will shorten the lifespan of our batteries. In our assumptions above we said we’d only drain the batteries down to 10%, meaning we can use 90% of the capacity.

25.6V x 230Ah x 2 x 0.9 = 10,598Wh or 10.6kWh usable capacity. Remember this number.

The first question is, “which loads in the list above can you run on a 3kVA inverter?” The answer is any one of them can run at any given time. But what if you want to run the air conditioner while blow drying your hair? 1200W + 1250W exceeds the inverter capacity of 2400W by 50W, and truth be told, the inverter can probably handle this slight overload for a couple of minutes if it’s not hot. But if you try to run anything else, the inverter will likely shut down to protect itself. So, one rule of thumb when using a 3kVA inverter is “you can run one major appliance at a time while also running several smaller loads”. 

For example, it’s no problem to run your microwave oven while watching TV, running your Starlink, and running a floor fan. But, trying to run the microwave and air conditioner at the same time for more than a couple of minutes is likely to cause a problem. This can be mitigated by using a larger inverter, two smaller inverters working together, not using more than one large appliance at a time, or using more efficient appliances. For example, the traditional RV rooftop air conditioner is a power hog. Replacing the air conditioner with an energy efficient unit that has a variable speed compressor will easily allow a 3kVA inverter to run the microwave, air conditioner, Starlink, and a TV all at the same time.

The second question is usually “how long can I run my electrical loads when off-grid?” I’ll use our examples above to illustrate this:

• Our electrical loads consist of:
  • Rooftop air conditioner consumes 1250W and runs 8 hours per day
    • 1250W x 8hrs = 10,000Wh per day
  • Microwave consumes 1200W and runs 10 minutes (0.17 hours) per day
    • 1200W x 0.17hr = 204Wh per day
  • Hair dryer consumes 1200W and runs 5 minutes (0.08 hours) per day
    • 1200W x 0.08hr = 96Wh per day
  • Coffee maker consumes 1400W and runs 5 minutes (0.08 hours) per day
    • 1400W x 0.08hr = 112Wh per day
  • Starlink consumes 35W and runs 24 hours per day
    • 35W x 24hrs = 840Wh per day
  • Floor fan consumes 75W and runs 4 hours per day
    • 75W x 4hrs = 300Wh per day

Answer #1:

If you add all those numbers you get 11,552Wh used per day, which exceeds the usable battery capacity of 10,598Wh. In other words, without some means of recharging the batteries, your camping trip will last almost one day.

Answer #2:

If you camp in the Fall when the weather is cool, you won’t need air conditioning, which reduces your daily energy consumption to 1,552Wh. If you take our usable battery capacity of 10,598Wh and divide that by the daily consumption of 1,552Wh, you get approximately 6.8 days before your batteries need to be recharged.

These are simplistic examples but they illustrate how to do the simple math to determine your needs. If you add means of recharging your battery while you are camping, then you can extend your electrical runtime accordingly. Part two of this series will add in solar energy production so we can see how that affects our ability to camp longer before needing to plug in somewhere to recharge the batteries.

Key Takeaways:

• A single Victron Energy 3kVA inverter will allow you to run one large appliance, or multiple smaller appliances, at any given time. This is usually sufficient for the casual camper or the frugal camper. But, it also means you must be aware of what electrical appliances are running at any given time, and you may have to first make sure no one is warming up breakfast in the microwave when you want to blow dry your hair.
• How much battery capacity tells you how long you can you run stuff before needing to plug in to recharge.
• Running air conditioning off-grid is usually the single largest electrical load in an RV. If you have multiple air conditioners, then double or triple the energy needs. It’s very doable to run air conditioning off-grid for days or weeks at a time, but it requires a larger battery bank and a means of recharging batteries relatively quickly. Often this involves solar on the roof and potentially a portable generator to make up the difference, especially on hot days.
• The corollary to the previous bullet is to try and camp in mild weather and/or switch to energy efficient appliances whenever possible.

Ready to Build Your Off-Grid Power System?

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