Water blaster (pressure washer) on a portable power station

Rated input power from Kärcher’s NZ product pages and datasheets (220–240 V, 50–60 Hz) and Kärcher’s 2025 ANZ comparison chart. These are Kärcher’s ratings, not QuietWatt measurements:

• K 2: 1.4 kW (1,400 W), max 1,750 psi, 6 l/min — K 2 NZ datasheet.
• K 3: 1,700 W, max 1,950 psi, max 6.9 l/min, 5 m power cable — K 3 (Kärcher NZ).
• K 4 Compact: 1.9 kW (1,900 W), 2,100 psi, 7 l/min — K 4 Compact (Kärcher NZ).
• K 5 / K 7: 2,100 W and 2,200 W per Kärcher’s 2025 ANZ comparison chart (karcher.com.au).

Start-up surge: TBD. Kärcher doesn’t publish a motor start-up figure on these pages. A water blaster motor starts every time you squeeze the trigger, so treat the rated input as the minimum continuous rating you need and want surge headroom on top — see peak vs continuous watts.

Other brands: read the rating plate on your own machine (Ryobi, Ozito, Bosch, etc.). QuietWatt won’t guess their watts. A watt meter on a mains socket beats any label.

NZ pass-through catch: Jackery NZ’s own FAQ for the Explorer 2000 Pro says that while it is charging from AC, max output drops to 1,800 W (2,200 W only when running from battery or DC/solar). So a K 4 that runs fine off the battery may trip the station if you plug the station into the wall at the same time — see pass-through charging.

Minutes ≈ (station Wh × ~0.85) ÷ blaster watts × 60. The ~0.85 is a planning allowance for inverter losses, not a spec. It assumes the motor runs flat out at its rated input the whole time — real spraying with trigger pauses (the motor stops when you let go) will stretch this; actual draw while spraying is TBD per machine.

Worked examples (arithmetic only): K 2 (1,400 W) on a 1,024 Wh station: 870 ÷ 1,400 ≈ about 37 minutes. K 3 (1,700 W) on the 2,160 Wh Explorer 2000 Pro: 1,836 ÷ 1,700 ≈ about 65 minutes. K 4 Compact (1,900 W) on the 2,048 Wh C2000 Gen 2: 1,741 ÷ 1,900 ≈ about 55 minutes.

• You still need water. A plug-in blaster is fed from a garden hose tap. If you’re away from a tap, check your machine’s manual before drawing from a tank — QuietWatt won’t guess.
• Keep the station dry and upwind of the spray. Most stations aren’t water-rated. Park it well back from the overspray, off wet ground, and use the blaster’s own cable rather than a long, thin extension lead — extension lead notes.
• RCD protection: outdoor wet work is exactly where you want a portable RCD. Check whether your station’s outlets are protected; not electrical advice.
• Pure sine output suits the motor — pure sine wave. Confirm pure sine on each listing.
• Solar won’t keep up with a 1.4–2.2 kW load; recharge between jobs — how many solar panels.
• Battery tool alternative: if you only wash the car or bikes away from power, a cordless water blaster on a tool-battery platform may be simpler than a 2 kWh station — see charging cordless tool batteries.