Size your RV inverter to the largest combination of AC loads you'll run at once, then add ~20% headroom. Most campers land on a 1,000–2,000W pure sine inverter; add an induction cooktop, microwave or air conditioner and you're looking at 3,000W+. This guide shows you how to add up your loads, why pure sine matters, and when to choose an inverter/charger instead of a standalone inverter.
Step 1 — Add up your AC loads
List the 120V devices you'll run and their running watts; note that motors and microwaves draw a surge several times higher at startup. Size the inverter to the biggest set of loads running together — not the sum of everything you own.
| Device | Typical running watts |
|---|---|
| Laptop / TV | 50–150W |
| Coffee maker | 800–1,200W |
| Microwave | 900–1,500W |
| Induction cooktop | 1,500–1,800W |
| RV air conditioner | 1,200–2,000W (higher surge) |
Step 2 — Size the inverter
| What you run | Inverter size |
|---|---|
| Devices, charging, small AC | 1,000–1,200W |
| Microwave or coffee maker | 2,000W |
| Induction / AC / multiple loads | 3,000W+ |
Bigger inverters pull serious DC current — confirm your battery and cabling can supply it (see the cable & fuse sizing chart and battery buying guide).
Step 3 — Pure sine vs modified sine
Choose pure sine for anything modern — it runs sensitive electronics, motors, and microwaves cleanly and quietly. Modified sine is cheaper but can buzz, run motors hot, and upset some chargers and medical devices. For an RV, pure sine is the right call.
Step 4 — Inverter or inverter/charger?
A standalone inverter just makes AC from your battery. An inverter/charger (like the Victron MultiPlus) also charges the battery from shore/generator and switches between shore and battery power automatically. If you use shore power at all, the inverter/charger is usually worth it.
- Shop standalone inverters
- Shop inverter/chargers — see also MultiPlus vs Quattro and how to install a MultiPlus
Our picks by use-case
- Light AC use (1,200W): pure sine inverter for devices and small appliances.
- Kitchen loads (2,000W): runs a microwave or coffee maker; consider an inverter/charger.
- Full off-grid (3,000W+): inverter/charger feeding induction/AC from a large lithium bank.
FAQ
What size inverter runs an RV air conditioner?
Most RV ACs need a 2,000–3,000W inverter with surge headroom and a strong battery bank — check your AC's running and starting watts.
Pure sine or modified sine for an RV?
Pure sine — it runs modern electronics and motors cleanly. Modified sine can cause buzz, heat, and compatibility issues.
Do I need an inverter/charger or just an inverter?
If you ever use shore power or a generator, an inverter/charger adds charging and automatic transfer in one unit — usually worth it.
Will a big inverter drain my battery?
Inverters draw from the battery whenever AC loads run; size your battery bank and charging to match — see the battery buying guide.
Find the right unit: Shop RV inverters & inverter/chargers — in stock, ships from Upland, CA.