An inverter converts the 12V DC power from your batteries into 120V AC power — the same kind of electricity you'd get from a wall outlet at home. You need one any time you want to run a household appliance: coffee maker, laptop charger, TV, blender, hair dryer, or air conditioner.
The question is: how big does it need to be? The answer depends on what you want to run, whether you'll run multiple things simultaneously, and how much you're willing to spend.
01 PURE SINE WAVE VS MODIFIED SINE WAVE
There are two types of inverters, and this choice matters more than the wattage:
Pure sine wave inverters produce clean, smooth power identical to what comes out of your home's wall outlets. They work with every appliance, produce no electrical noise, and are safe for sensitive electronics. This is what you should buy.
Modified sine wave inverters produce a rough, stepped approximation of AC power. They're cheaper but can cause buzzing in audio equipment, overheating in motors, glitches in digital devices, and damage to some appliances over time. AC compressors, CPAP machines, and many chargers don't play well with modified sine.
The price gap between modified and pure sine wave has narrowed significantly. A quality 2,000W pure sine inverter runs $150–$300. It's not worth saving $50–$100 on modified sine and risking damage to a $300 CPAP machine or a $1,500 laptop. Pure sine is the standard recommendation for any RV solar system.
02 HOW TO SIZE YOUR INVERTER
Inverter sizing comes down to two numbers: continuous wattage (what it can sustain indefinitely) and surge wattage (what it can handle for a few seconds during motor startup).
To find your size: add up the wattage of everything you might run at the same time. Not everything you own — just the things that could realistically be on simultaneously. Then add 20–25% headroom.
Common RV Appliance Wattages
03 RECOMMENDED SIZES BY USE CASE
1,000W inverter: Laptop, TV, phone chargers, CPAP. No high-draw appliances. Perfect for minimalist setups and van life. Cost: $100–$200.
2,000W inverter: Everything above plus coffee maker, Instant Pot, microwave (one at a time), and a residential fridge. The sweet spot for most RVers. Cost: $200–$350.
3,000W inverter: Everything above plus air conditioner (with soft-start kit), hair dryer, and ability to run multiple high-draw appliances simultaneously. Required for AC on solar. Cost: $350–$600.
Larger inverters consume more power even when nothing is plugged in. A 3,000W inverter might draw 15–30W just sitting idle — that's 360–720Wh per day doing nothing. Use the inverter's power switch (or a remote switch) to turn it off when you don't need AC power. Many RVers run their 12V devices directly from the battery and only switch the inverter on when they need an AC outlet.
04 INSTALLATION NOTES
Inverters draw enormous current from 12V batteries. A 2,000W inverter at full load pulls roughly 170A at 12V. This requires very thick cables (2/0 AWG or larger) between the inverter and battery bank, kept as short as possible. A proper fuse or circuit breaker on the positive cable is mandatory.
Mount the inverter close to your battery bank (within 3–5 feet ideally) in a ventilated space. Inverters generate heat under load and need airflow to stay cool. Don't bury them in a sealed compartment.
FIND THE RIGHT INVERTER
Pure sine wave inverters from Renogy, Victron, and AIMS — matched to your system and budget.
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