How do I size a mobile power supply for tools?

Rule of thumb: the continuous power must cover the sum of the devices running simultaneously, and the peak reserve must handle the highest individual inrush current. Plan for 20–30 % reserve. The GM 3600 offers 3.6 kW continuous and up to 18 kW peak.

Can a 3.6 kW battery power unit supply a construction site?

For one to two professional tools running simultaneously plus inrush peaks, yes. With 3.6 kW continuous and up to 18 kW peak, the GM 3600 covers most handheld and bench devices.

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How much power do construction tools need?

A wattage overview of the most common professional devices – with inrush factor. This is how to find out whether your mobile power supply is sufficient.

Green MeOH GmbH · 06/2026 · Reading time approx. 4 min.

Power table of common tools

The rated power (watts) applies during operation. Devices with a motor or compressor also draw an inrush current at startup (more on this in the inrush current guide). Both values count for sizing.

Tool	Typical continuous power	Inrush factor
Angle grinder (125–230 mm)	1.2–2.6 kW	2–3×
Rotary hammer / combi hammer	0.8–1.5 kW	2×
Handheld circular saw	1.2–2.2 kW	2–3×
Table / mitre / sliding saw	1.6–3 kW	2–4×
Core drill (diamond)	2–3.5 kW	2–3×
Mortar / screed mixer	1.6–2.5 kW	3–5×
Construction compressor	1.5–3 kW	3–5×
Submersible / dirty-water pump	0.8–2.2 kW	5–7×
Pressure washer	2–3 kW	3–4×
LED work light	0.05–0.2 kW	1×
Inverter welder	2–5 kW	high brief peaks

How to size it correctly

Continuous power: sum of all devices running simultaneously.
Peak reserve: the highest individual inrush current (don't add up all startups – but safely cover the largest one).
Reserve: plan for a 20–30 % buffer; don't run permanently at the limit.
Sine waveform: pure sine for motors and electronics.

Example: Handheld circular saw (2 kW, inrush ~6 kW) + LED work light (0.2 kW). Continuous demand ~2.2 kW, highest peak ~6 kW. The GM 3600 (3.6 kW continuous, up to 18 kW peak, pure sine) covers this with reserve to spare.

GM 3600 – 3.6 kW continuous, up to 18 kW peak

Enough reserve for high-inrush professional tools. Emission-free, from €2,999 net.

To the GM 3600 & comparison →

Frequently asked questions

Why isn't the wattage on the rating plate enough?

The rated power applies during operation. Motors and compressors draw a multiple of it at startup (inrush current). For the power source, this brief peak also counts.

How do I size the power supply?

Continuous power = sum of devices running simultaneously; peak reserve = highest individual inrush current; plus 20–30 % reserve. The GM 3600 offers 3.6 kW continuous and up to 18 kW peak.

Is a 3.6 kW unit enough for the construction site?

For one to two professional tools running simultaneously plus inrush peaks, yes – that covers most handheld and bench devices.

Read on: Inrush current: up to 18 kW starting power · Power station & welder · Battery power unit vs. diesel generator

Note: All values are guide values. The rating plate or the manufacturer's specification of the respective device is authoritative.