A power outage during a storm, running power tools far from an outlet, or simply needing independent power on your plot — in every one of these situations, having the right generator on hand makes all the difference. The problem is that the range of generators on the market is huge, and picking a model that's too weak means it won't handle the startup surge of a fridge or a compressor, while an oversized one means paying for power you'll never actually use. This guide shows you how to calculate the power you need, what separates a conventional generator from an inverter model, and which one fits your situation.
How to choose generator power?
The starting point is adding up the power draw of everything you plan to run at the same time. What matters isn't just rated (continuous) power — it's also starting power. Appliances with an electric motor (a fridge compressor, a well pump, an angle grinder) can draw 2–3 times more current the moment they start up than during normal running. That's why every generator spec sheet lists two numbers: rated power (the continuous output the unit can sustain) and maximum power (the short burst available during startup).
For lighting, chargers, small electronics, and a single garden tool, a generator with 2000–2800 W rated power is enough — for example the Weima WM2500B (2000 W rated, 2500 W max). If you need to power several household appliances or construction power tools at once, a 3500–5000 W model is a better fit. To keep an entire house running during an outage (fridge, boiler, lighting, heating pump) or to run high-draw equipment, you'll need 5000–7500 W of rated power, like the Weima WM5500BE or the Weima WM8500E.
Conventional or inverter generator — which to choose?
A conventional (synchronous) generator, like the Weima WM3200B or the WM3200BE, produces electricity directly through an alternator driven by a combustion engine. It's a simpler design, usually cheaper for the same power output, and built to handle heavy loads — a good fit for construction sites, workshops, or emergency home backup. The trade-off is louder operation (77–86 dB) and less stable voltage, which matters if you're powering sensitive electronics.
An inverter generator, like the Weima WM2300iS, converts electricity electronically, which makes the output voltage far more stable — safe for laptops, home electronics, phone chargers, or medical equipment. Inverters also run quieter (65–77 dB) and are lighter at comparable power, which anyone who packs a generator for camping or a weekend cabin will appreciate. Models like the Weima WM4000i or the Weima WM6000Ei combine higher power (3500–5500 W rated) with the benefits of inverter technology, so they work well even for heavier power needs.
Conventional vs. inverter generator — comparison table
| Feature | Conventional generator | Inverter generator |
|---|---|---|
| Voltage stability | standard, can fluctuate under load | high — safe for electronics |
| Noise level | 77–86 dB | 65–77 dB |
| Weight at similar power | higher (43–105 kg) | lower (18–65 kg) |
| Price at the same power | usually lower | usually higher |
| Best for | construction sites, workshops, home backup power | camping, electronics, working near people |
Which generator to choose: home, construction site, or off-grid plot?
Home backup power — if keeping the fridge, lighting, and heating running during an outage matters to you, a 5000–7500 W rated model is a good fit, such as the Weima WM5500BE (5000 W rated, electric start, roughly 9 hours of runtime at 2/3 load), or the more powerful Weima WM8500E (7500 W rated) for heavier demand.
Construction and workshop use — for running power tools (a drill, an angle grinder, a low-current welder) and site lighting, a solid mid-range conventional generator works well, such as the Weima WM3200B (2800 W rated, electric start) — built to handle appliances with different power draws switching on and off frequently.
Off-grid plots, camping, and voltage-sensitive gear — if quiet operation and safe power for a laptop, a portable fridge, or home electronics matters most, choose an inverter generator, such as the compact Weima WM2300iS (18 kg, 65 dB) for trips, or the Weima WM4000i if you need more power while keeping quiet, stable operation. It's the right pick for anyone who wants a light, quiet unit that fits easily in a trunk yet can still power several devices at once.
Before settling on a specific model, check the starting mechanism too — some generators, like the Weima WM3200B or the Weima WM5500BE, come with electric start, so you fire them up with a single button press instead of pulling a cord — especially handy in cold weather or with frequent daily use.
Frequently asked questions about generators
What generator power do I need for a fridge and a heating boiler during a power outage?
Count not just the rated power of your appliances, but their starting power too — a fridge compressor and a heating boiler pump can draw 2–3 times more current the moment they start than during continuous operation. For a typical single-family home, a generator with 5000–7500 W of rated power is usually enough.
What's the difference between rated power and maximum power?
Rated power is the output a generator can sustain continuously without risk of overload. Maximum power is a short-burst figure, typically available for a few to a dozen or so seconds, used during the startup of appliances with electric motors.
Is an inverter generator safe for a laptop and other electronics?
Yes, that's its main advantage. Because it converts electricity electronically, an inverter generator's output voltage is far more stable than a conventional model's, protecting sensitive electronics from damage.
How much fuel does a generator use?
It depends on the model and load — manufacturers typically list consumption in grams per kilowatt-hour (for example, 375 g/kWh on Weima inverter models) along with an estimated runtime on a full tank at 2/3 load, which for our generators is usually 6–11 hours.
Does a generator need an electric starter?
It's not required, but it makes life easier — some models, like the Weima WM3200B or the Weima WM5500BE, have an electric starter alongside the classic pull-cord, which is handy when you're starting the unit often in cold weather.
Need advice?
You'll find the full range of conventional and inverter generators in the generators category. If you're not sure what power output fits your appliances, call us: +48 780 140 444 — we'll help you pick the right generator for your needs.
Published: 16.07.2026 · Motohill Team