Kärcher WV 6 Plus at EUR 79.99: about 300 m2 per charge, so divide by your own glazed area

You open the curtains on a November morning and the inside of the glass is filmed with water; a towel just leaves streaks running down, and by the afternoon those streaks are still there once it dries. Dutch housing is full of single glazing and early double glazing, and that film is not dirt, it is the temperature difference between inside and out, which a cloth only pushes somewhere else. The Kärcher WV 6 Plus is a cordless window vac: a blade pulls the water off while the machine draws it into a small tank in the body, so the glass is left without streaks and nothing runs down onto the sill or the floor. bol.com sells it itself for EUR 79.99, rated 4.2 from 89 reviews, 57 of them five stars.

Kärcher is a German cleaning-equipment manufacturer and the WV range is where it shrank its industrial wet-pickup idea down to a household tool. The official specification states a 280 mm working width, 100 minutes of continuous use from a full charge, a 170-minute charging time, a body of 126 x 280 x 310 mm at 0.8 kg with the battery, and a charge indicator that Kärcher describes as accurate to the minute; it also claims windows come clean three times faster than by traditional methods. The long suction strip is described as making edge cleaning more flexible, and the bol specification table adds that this model is 10 W on a 3.65 V lithium-ion cell with a 0.15 l dirty-water tank.

What deserves calculating is not the battery but the tank. Kärcher rates the coverage at roughly 300 m2 per charge, so copy this line: the glazed area you want to clean divided by 300 = how many rounds one charge covers. A Dutch flat rarely has more than about 20 m2 of window glass, so the answer is almost always that a single charge is never used up. Put two of the machine's own numbers side by side, though, and something else appears: 300 m2 of endurance is paired with a 0.15 l dirty-water tank, which works out at 2,000 m2 per litre of collected water. That ratio cannot hold, so the tank fills long before the battery empties. In other words, what decides how often you stop is emptying the tank, not charging it, and the question to ask before buying is how far the sink is from the window rather than whether the runtime is enough. The electricity is a non-issue: 10 W over a 170-minute charge is about 0.028 kWh for a full charge, and multiplying that by your own price per kWh gives a figure too small to add up over a year.

• Whether the price is genuinely low: the bol page shows a Kärcher recommended price of EUR 119.95 against the current EUR 79.99, sold by bol with next-day delivery, 30-day returns, and more than 100 sold last month. The manufacturer's own site carries the same current price in the same period, so this is not a bol-only discount but simply what the machine costs now. (source 1)
• The use that actually earns its keep in winter is not the outside of the window but the morning condensation: pull it down in strips, with no cloth needed afterwards and no water pooling on the sill, which is exactly where the mould line forms along the bottom of the frame in Dutch rentals. (source 2)
• Before ordering: a spray bottle, a microfibre cloth and a detergent concentrate come in the box, so nothing else is needed the first time; the blades lift out to be washed separately, and rinsing them after use matters, because dried limescale left on the rubber is what starts the streaking. (source 2)

Price

bol.com EUR 79.99・Kärcher recommended price EUR 119.95

Rating

4.2 on bol・89 reviews (57 five-star, 10 one-star)

Specs

Working width 280 mm・dirty-water tank 0.15 l・100 minutes runtime・170 minutes charging・10 W・3.65 V lithium-ion・126 x 280 x 310 mm・0.8 kg with battery・charge indicator accurate to the minute

Platform

bol.com, sold by bol, EAN 4054278976471, manufacturer reference 1.633-741.0

Checked

18 September 2026, the bol listing and the kaercher.com specification page

Hokimi field note: run the first pass horizontally along the very top of the pane, then work vertically downwards, so the water runs onto glass you have not done yet and one window takes two passes. Empty the tank at halfway rather than waiting for full: once it is full, tilting the body sends water back out of the nozzle onto the glass you have just finished. The bol link on this page is an affiliate link: Hokimi may earn a commission if you order through it, at no extra cost to you. Price and rating checked on 18 September 2026.