This top-spec window vac has a huge discount - and we've tested it

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If you've never used a window vac before, you simply won't know what you're missing. It's the quickest and simplest way to clean any shiny surface. I love harnessing technology to help with household chores, and that's exactly what a window vac does. 

I've tested plenty of them over the years, from cheap Lidl versions, to the most expensive models on the market, and I quickly learned that you get what you pay for. 

And that's why I'm a huge fan of Karcher's range. It's the company that most of us will associate with high-quality jet washes, but its window vacs are pretty much the best you can buy. 

The current range starts off with the basic but excellent WV 1, which is currently priced at £39.99, but if you want the very best, you can go for the new WV 6 Plus, which is the one I've been testing. 

It's currently available for £79.99 thanks to a limited-time deal on Amazon, bringing its price down from the usual £109.99 - and it's a fabulous bit of kit for that money. 

Its key strength is its huge battery, which gives 100 minutes of run time. And it has a large capacity waste tank. So it's ideal for doing big jobs, or cleaning things while off grid for a while. 

To use a window vac, you just need to spray on some detergent from the supplied bottle and use the attached microfibre cloth to rub it across the glass or tiled surface. 

Once the panel is completely covered, you power up the window vac, and in neat swipes, just suck up the residue. The liquid is inhaled through the squeegee into the waste tank and you're left with a very shiny panel, with no streaks. It's such a quick and easy thing to do. 

A new feature I love in the WV 6 is the battery indicator, which gives a minute-by-minute countdown of how much power is left. It's so much more informative than a set of lights. It also has a very wide squeegee, which was a big bonus in my conservatory, with its full-height windows. 

There's a version available, the WV 6 Plus N, which comes with an extra narrow head attachment, and this is handy for another of the window vac's many uses, demisting car windscreens. 

I go away a lot in a motorhome, and I also have a boat, and a window vac is one of the most useful tools I take with me. If I wake up in the morning to find my window covered in condensation - a daily occurrence in the colder months - I can just suck it up. It's such a chore to do this with a chamois or sponge, but with a window vac it literally takes seconds. 

The WV 6 Plus is also the quietest window vac I've used, which is useful on peaceful campsites, and it's really easy to take apart and clean. 

The only issue I had while using on my particularly filthy external windows was having to clean out the squeegee after each wipe. Dirt collects easily in the rubber layers, and this will lead to losses of suction along its length, and that causes streaks. 

It's a job that takes a couple of seconds, and I didn't find I needed to do it on the cleaner insides of the windows, but giving it a quick wipe with my fingers became part of the routine after each pass. I also found the screw-cap on the spray bottle needed tightening periodically, or it would leak a little when held at an angle. But, again, this wasn't a big job. 

But I'm amazed at how well the battery stood up to the challenge. After doing my entire conservatory, several other windows in the house, and then taking it away for a chilly week's holiday in my motorhome, it still had the best part of an hour left in the battery. 

If you don't need this huge battery capacity, but you'd like the same basic functionality of the flagship WV 6, take a look at the WV 2 Plus N, because it's got the biggest saving on Amazon at the moment. It's actually terrific value for money, priced at £46.99 thanks to a saving of 41%. The waste tank isn't as big, and the battery won't last for 100 minutes, but it'll do a superb job for a much lower price. 

We don't know how long Amazon will have the sale for, and how long stocks will last, so if you fancy trying out a window vac for a decent price, this is a great opportunity.