Clip-on tools include a 2-in-1 furniture nozzle with pull-down dusting brush and a bonkers long and very flexible crevice tool. That is ideal for getting down behind radiators, but takes some wielding to accurately pinpoint spots of dust. A good-length metal tube optionally extends reach for all tools. Clips and fittings between tools and tubes are top-notch. The Bosch Unlimited has a size of 130 cm (51.2 inches) from top to bottom. That’s about the same as most other cordless vacuum cleaners on the market. Most people can vacuum comfortably with this size. Unusually, the BCS122GB has a single filter unit, rather than the multifarious foam, paper, mesh and pleated filters of its rivals. But thanks to Bosch’s very sleek filter design that doesn’t diminish the filtration, and the company claims that a hygienic 99.9% of particles will be captured. Thankfully, because of the two batteries, this Bosch delivers plenty of serious Turbo-mode cleaning runtime. With the fast charger taking 55 minutes, power is not quite unlimited, but you can get a very long way around the house in 18 minutes. Bosch Unlimited BCS122GB – How noisy is it? In constant use, we got single-battery run times a fair bit longer than Bosch’s claims. These ranged from a truly staggering 89 minutes on normal power mode with just a detail tool attached, to a fairly respectable nine minutes on Turbo power mode with the floorhead running. An hour and half of cleaning from a single battery is our new vacuum cleaner runtime record by miles – and you get two batteries. Three hours of vacuuming anyone? No, us neither.

The handle is directly on the motor. That ensures a comfortable feeling when holding the vacuum cleaner. The Bosch Unlimited has two cleaning modes – standard and “Turbo” – which you can toggle between by pressing a button on top of the vacuum’s pistol-grip handle. While the standard mode will get you plenty of battery life, it isn’t particularly effective, producing only 4.5kPa of suction. The brush is 25 cm (9.8 inches) wide, and its roller has a width of 21 cm (8.3 inches). That size is entirely sufficient for cleaning. We even reached the corners and got under most of our furniture. Things change when Turbo is engaged but the Bosch still isn’t great. It’s more powerful this time than the Beldray but lags behind the Dyson, Xiaomi and Shark vacuums. The Bosch Unlimited 8 has two vacuuming settings: normal and turbo. Likewise, the Bosch Unlimited 8 features three cleaning modes: eco, auto, and boost. In Turbo and Boost modes, these vacuums will, of course, have the most suction, making them the best cleaners they can be. Those are also the settings I used for my tests. Hard floors

A decent enough cordless vacuum cleaner but rivals offer more for the same price

The head’s superb articulation allows it to turn into all but the tightest of turning steps, although it remains too large to flip up and do the verticals. For those, we used the triangular upholstery tool, which was effective if not swift. Both floorheads of the Dyson V15 did a great job of limiting the hair wrap issue. Its High Torque 2.0 floorhead also features a row of fangs, which help send most of the vacuumed hair into the dust cup instead of letting it end up on the roller. Thanks to that, it is unnecessary to spend minutes cleaning the roller after each cleaning session. The Bosch came out with flying colours in our cleaning test thanks to the super-strong suction power . The cordless vacuum cleaner sometimes removed even more dirt from the carpets than we had spread on them. An essential advantage of cordless vacuum cleaners is the "2-in-1 function". It increases versatility in use enormously. Now you can also use it to clean your car.

The Dyson V15 still shines brightly on both low and high carpets with the High Torque 2.0 floorhead. The only issue I initially had was finding it a little challenging to push the machine on my high carpets. But then I adjusted a slider on the floorhead, and everything was okay. Hair This is less powerful than the low power modes on all its key rivals. The Dyson V8 and V7 are far more powerful, as are the Xiaomi Roidmi F8 and X20 and the Shark DuoClean Wireless. Even the budget Beldray Airgility Max produces more suction than the Bosch at low power. The Dyson V15 sports an LCD screen that shows maintenance alerts, estimated remaining battery life, the current cleaning mode (eco, auto, or boost), how many dust particles are vacuumed, and their size (10, 60, 180, and 500 microns). Another unique feature of the design is the exchangeable battery of the Bosch Unlimited Pro Power. You can remove the battery at the push of a button and insert a new one. Bosch was one of the first manufacturers in the UK to implement this, and many have followed suit.

Why you can trust us

Joe, our wireless vacuum expert on the Smart Home Fox team, has spent over half a decade meticulously testing every model that has landed with us. However, those huge runtime differences highlight the equally massive difference in suction power between modes, and we think Bosch has got it very wrong here. Except, in fact, you can: the Vax ONEPWR Blade 5 Dual Pet & Car comes with all the attachments you might need and a second battery. While those batteries don’t last as long as the Bosch’s, its soft roller helped it perform better in our all-round cleaning tests. That is a trait we are much more used to seeing with air-powered ‘turbo’ brushes and it can make cleaning rather frustrating. The floorhead’s cleaning power is great, but the brush bar slowed or stopped far too often on carpet for our liking. Switching to normal power mode stops that happening – but the clean is then fairly poor. The Bosch brings 3.2 kg (7 lbs) to the scale. That’s a real heavyweight among cordless vacuums, and it shouldn't get much heavier.

All in all, the BOSCH Unlimited Pro Power BSS81POW1 cordless vacuum impressed with its extremely powerful suction in the cleaning tests. We have little doubt Bosch has specified a lower torque brush bar motor to save power and increase runtime but – like the ineffective normal power mode – it’s a false economy. We would happily trade a couple of minutes of Turbo runtime for a brushbar that cleaned consistently without slowing or stopping. It’s not an issue we have experienced with Bosch’s premium competitors either. That alone lets down an otherwise excellent carpet-cleaning performance. This combination allows Bosch to claim ‘unlimited’ runtime for this cleaner. On standard power setting, it will go for an hour, and the charger can power up a battery in 55minutes. With the two batteries, theoretically, you simply won’t run out of power.

The Dyson V15 wins 2-1 and draws once against the Bosch Unlimited 8. The Dyson V15 passed all of my tests with excellent results, is lightweight, isn’t too noisy, and comes with various attachments. The Bosch Unlimited 8 is also a good choice, but it is a bit heavy, has a small dust cup, and isn’t ideal for deep cleaning carpets. Cleaning Performance We would have much rather seen the normal mode offer twice the suction and half the runtime. That would give you about half an hour of ‘normal’ cleaning with the floorhead per battery. As it is, with its two batteries, the Unlimited BCS122GB offers over two hours of not very much at all on normal mode. As it is, the normal mode provides ineffectively low suction power. It’s of very little use in typical day-to-day household cleaning and I guarantee most users will simply default to the Turbo setting all the time. At which point, nine minutes is not much at all for general floor vacuuming duties. Good job Bosch supplies two batteries. For one thing, you have to disassemble the device entirely whenever you want to empty the container because the individual parts are arranged that way. We would have expected a better system from the traditional company. The runtime of the BBS1U224 from the 8 series is about 40 minutes, which is also quite short. There are many devices with a longer battery life these days.