For most caravans and touring setups, a 2000W pure sine wave inverter is the practical starting point if you want to run a coffee machine, microwave or a 1600W induction cooktop—one major appliance at a time. A 3000W inverter is generally for larger appliances, more starting headroom or running two heavy loads together. The appliance label, surge requirement and battery system still decide the real answer.
Coffee machine around 1250W: usually 1500–2000W. Microwave around 1250W: usually 2000W to leave starting headroom. Induction cooktop around 1600W: normally 2000W when used alone. Choose 3000W only when the appliance or simultaneous load genuinely needs it and the battery, BMS, cabling and protection can supply it.
Those are planning ranges, not universal product guarantees. Check the input wattage on the exact appliance—not its cooking output, heat output or model name—and follow the inverter manufacturer's continuous and surge limits.
Quick caravan inverter size guide
| Inverter size | Typical use | Main limitation |
|---|---|---|
| 300–600W | Laptops, camera batteries and small electronics | Not suitable for normal heating or cooking appliances |
| 1000W | Tool chargers, small kitchen appliances and light 240V loads | Usually too small for a normal coffee machine, microwave or induction hob |
| 1500W | Some capsule coffee machines and single medium loads | Limited headroom; appliance startup behaviour matters |
| 2000W | Coffee machine, microwave or 1600W induction cooking—normally one at a time | Can draw close to 190A from a 12V battery at full output |
| 3000W | Higher-powered appliances or selected simultaneous loads | Roughly 280A at full output; the 12V side becomes a serious installation |
Examples assume a 12V system and roughly 88% conversion efficiency. Your appliance and inverter specifications take priority.
What size inverter does a coffee machine need?
A caravan coffee machine drawing about 1250W generally points to a 1500W or 2000W pure sine wave inverter. The 2000W option provides more breathing room and is less likely to be operating at its absolute continuous limit every morning.
Do not size it from the word “coffee” alone. Pod machines, domestic espresso machines, milk heaters and kettles can all have different input ratings. Check the plate or manual for the exact wattage and whether the manufacturer identifies a higher starting load. REDARC's current Australian sizing guide similarly places capsule coffee machines around the 1200W inverter tier and larger heating appliances higher; treat that as a category guide rather than a substitute for the appliance label. See REDARC's inverter guide.
What size inverter does a microwave need?
A microwave with roughly 1250W electrical input is normally better matched to a 2000W inverter than a 1500W unit. Microwaves can pull more from the wall than the cooking watts shown prominently on the front, and startup can make a marginal inverter trip even when the advertised cooking output looks safe.
Look for input power on the appliance plate or manual. If only the cooking output is shown, do not assume that is the inverter load. REDARC recommends allowing additional headroom rather than matching the inverter exactly to the running watts, particularly for a microwave. See REDARC's sizing explanation.
What size inverter does an induction cooktop need?
A 1600W single-zone induction cooktop generally needs a 2000W pure sine wave inverter when it is the only major appliance running. If you want to run it with a coffee machine, microwave or another large load, add the simultaneous input watts first; that can push the system into 3000W territory very quickly.
Turning an induction hob down does not always create a perfectly steady low load. Some units regulate heat by pulsing the element, so the inverter may still see close to the cooktop's rated power during each on-cycle. Size for the maximum demand the appliance can present, not only its average energy use over dinner.
The inverter rating is only half the answer
A large inverter converts a relatively low 12V supply into 240V power. That means the battery-side current is much higher than many people expect:
Battery current = appliance watts ÷ battery voltage ÷ inverter efficiency
| 240V load | Approx. 12V battery current |
|---|---|
| 500W | 47A |
| 1000W | 95A |
| 1250W | 118A |
| 1600W | 152A |
| 2000W | 189A |
| 3000W | 284A |
These are rounded planning figures at 12V and 88% efficiency. Actual current changes with battery voltage and inverter efficiency. REDARC recommends dividing the load by the real battery voltage and accounting for efficiency; Victron also directs installers to use the cable and fuse requirements in the exact inverter manual. REDARC current-draw guidance and Victron DC wiring guidance.
I started with a 1000W inverter and later moved to a 2000W unit with my lithium setup. The useful lesson was that the bigger number on the inverter was only the start. Once the load moved into that range, the battery's continuous-discharge rating, BMS, cable run, fuse and connections mattered just as much as whether the inverter said 2000W on the case.
Does a 2000W inverter mean you need a 200Ah battery?
Not automatically. Inverter watts describe how much power can be supplied at one moment; battery amp-hours describe how much energy is stored. A short coffee run can use relatively little capacity while still demanding well over 100A. The battery must pass both tests: enough usable Ah for the day and enough continuous current through its BMS for the peak load.
For example, a 1250W coffee machine used for nine minutes is roughly an 18Ah battery load using AMP'D's conservative 12V/88% assumptions. That may fit comfortably inside a charged 100Ah lithium battery's energy budget, but only if that battery and its BMS can safely provide the current. Two batteries with the same 100Ah label can have different discharge limits.
If battery sizing is the part you are weighing up, compare 200Ah versus 300Ah lithium and then run the complete setup through the calculator.
Can you run coffee, the microwave and induction together?
Usually not on a 2000W inverter. Using AMP'D's planning inputs, a 1250W coffee machine and 1600W induction cooktop total 2850W before allowing for anything else. Add the microwave and the combined nameplate load reaches 4100W.
The practical approach is load management: run one heavy appliance at a time. That often avoids paying for a much larger inverter, battery bank and installation just to cover a few minutes of overlap.
Safety note: this is a sizing guide, not an installation guide. A 2000W or 3000W inverter can draw hundreds of amps on the 12V side and produces potentially lethal 230–240V AC. Have the battery discharge limits, cable size and length, fuse, isolation, earthing and fixed 240V work confirmed by appropriately qualified people and the exact equipment manuals.
Renogy inverter options close to these sizes
Renogy Australia currently lists pure sine wave inverter options in both 2000W and 3000W sizes. The 3000W model lists 6000W peak surge and greater than 90% conversion efficiency. Check the live specifications, battery requirements and manual before choosing either.
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Work out the inverter and battery together
Add the exact appliances you intend to run to the free AMP'D 12V calculator. It checks the largest simultaneous inverter load, estimates its battery current and then sizes battery capacity, solar and DC-DC charging from the whole day's use.