What Size Inverter Do You Actually Need for an RV?
In short, For basic electronics (laptops, phones, CPAP, TV), a 1,000W Pure Sine Inverter is plenty. If you want to run a microwave, blender, or single induction cooktop, step up to a 2,000W Inverter. If you want to start a 13,500 BTU rooftop RV air conditioner without tripping, you need a 3,000W Inverter paired with a soft-starter unit and at least 300Ah of lithium batteries.
Continuous vs Surge Wattage
Every inverter has two ratings on its spec sheet: Continuous Watts (what it can output for hours without overheating) and Surge / Peak Watts (what it can deliver for 1 to 5 seconds).
Resistive appliances like electric space heaters and curling irons pull steady power. Inductive motor loads — such as microwave magnatrons, blender motors, and refrigerator compressors — pull 2x to 3x their running watts the millisecond the rotor begins turning. An inverter with insufficient surge headroom will immediately trip into overcurrent shutdown.
Common RV AC Appliance Wattage Table
| Appliance | Continuous Running Watts | Startup Surge Watts | Minimum Inverter Size |
|---|---|---|---|
| Laptop / USB-C Charger | 65W – 100W | 120W | 300W |
| 32" Smart TV + Streaming Box | 60W – 80W | 100W | 300W |
| Microwave (700W Cooking Output) | 1,050W | 1,800W | 2,000W |
| Nespresso / Keurig Coffee Maker | 1,200W | 1,300W | 2,000W |
| Portable Induction Cooktop | 1,400W – 1,800W | 1,900W | 2,000W – 3,000W |
| Rooftop RV A/C (13.5k BTU) | 1,600W | 3,500W+ | 3,000W + SoftStart |
Why You Must Buy Pure Sine Wave
Never buy a "Modified Sine Wave" inverter to save $50. Modified sine wave produces a harsh, stepped block wave rather than a smooth 60Hz utility AC waveform. It causes variable-speed compressor motors to buzz loudly and overheat, burns out laptop power bricks, and can destroy digital microwave control boards. Always specify Pure Sine Wave.