Kärcher OC 6-18 Review UK (2026)

Buy the Kärcher OC 6-18 Premium if you want a cordless tank trolley for bikes, furniture and a careful rinse, you will fill it indoors, and you already run 18V Battery Universe packs or you will buy one. This review is only about the OC 6-18 Premium trolley: bare versus a pack, and when to walk away. The class shortlist is the cordless pressure washer with tank guide. The job page is bikes. The rest of the yellow range sits on the Kärcher hub.

It is not a lab test. Specs come from Kärcher. Street prices come from Amazon, Kärcher centres and UK shops in August 2026.

If you click through and buy, we may earn a commission.

This is a 12 litre 18V trolley, not a shed K4. Rated pressure is 24 bar. That is still well above a garden hose. It is not a mains substitute. It will not strip a mossy patio the way a tap-fed K4 does. Buy it because there is no outdoor tap and you refuse a bucket, or because the Battery Universe packs are already on the shelf. Do not buy it because the yellow badge looks like a K-series washer.

If you have a tap and a 13A socket, start on the Kärcher hub rather than paying trolley money for 24 bar. If you will drop a hose in a bucket, that is a handheld on the cordless guide. If you want a bigger tank and you are not already on Kärcher 18V, that is the Bosch Fontus review. First-use setup, nozzles and frost drain-down are on how to use a pressure washer.

Quick picks

Specs

	Bare listing	With a pack
Model	Kärcher OC 6-18 Premium, trolley only on the street listing	Same trolley. Official Battery Set is 1.328-522.0 (Trafalgar K1328522). Confirm whether a pack and charger are in the carton
Max pressure	24 bar, medium-pressure. Not a K2. Not a K4	Same pump
Flow	200 L/h	Same
Battery	18V Battery Power, the 18V Battery Universe packs, not in the box on the bare listing	Pack sold separately, around £58. The Battery Set carton may include a 2.5Ah pack and charger
Water	12 L trolley tank, or a tap. Optional suction hose sold separately	Same
Weight	5.7 kg without accessories. About 18 to 20 kg with a full tank and the 2.5Ah pack	Same trolley
Size	349 × 321 × 586 mm	Same
Runtime (Kärcher)	Up to 12 minutes on 2.5Ah, 24 minutes on 5.0Ah, if you already own a pack	Same, once you have that pack
Typical UK price, Aug 2026	£229.99 bare on Amazon. Some Kärcher centre listings from about £229 to £300	Matching 18V pack around £58. Shop the contents list and the live total

Prices checked August 2026. Bare tools and Battery Set cartons are different listings. Confirm whether a battery and charger are in the box. Shop the live total, not the word Premium on a tile.

Who it is for

This is the Kärcher tank trolley in the 24 bar class. Buy it if most of the list below is true.

• There is no outdoor tap, or you will not drag a hose through the hall, and you refuse to carry a bucket as a second object.
• The jobs are one or two bikes, garden furniture, toys, camping kit, and the odd careful car rinse with a refill.
• You already own Kärcher 18V Battery Universe packs, or you will buy a pack with the trolley and stay in that family.
• You accept 24 bar. You are not trying to strip moss or pretend this is a battery K4.
• You accept 12 minutes on a 2.5Ah pack. A 5.0Ah pack is the upgrade, not a bigger pump.
• You do not already own this trolley. If you do, buy a spare battery, not another OC 6-18.

That is the buyer the tank page already treats as the Kärcher pick. The bikes page treats it as the no-tap path if you will not carry a bucket. The Kärcher hub treats it as the cordless model you can actually buy in the UK. It is not the default household washer. That is still a mains K4 if the tap and the socket are there.

Skip it if

• You have a tap, a 13A socket and a patio or a weekly family car. This trolley is not a cheaper K4. 24 bar will rinse. It will not strip moss from a terrace. Start on the Kärcher hub. Leave this page.
• You will carry a bucket. A tank is convenience, not punch. A handheld on the cordless guide is lighter and usually stronger for less money. The water lives in the bucket. If that sentence does not put you off, you do not need this trolley.
• You are not already on Kärcher 18V and you want a bigger tank. That is the Bosch Fontus. Fifteen litres, 20 bar, a kit around £198 or £179 bare. The complete first buy is cheaper, and the tank is larger.
• You thought this was a battery K2 or K4. There is no widely stocked high-pressure battery K-series washer in the UK. Twenty-four bar sits a long way below 110 bar on a K2 and 130 bar on a K4. Buy this for the tank and the brand, not as a tap-fed K4 with the lead cut off.
• You wanted an OC 3. That is a 5 to 6 bar rinser with a small jug. Fine for boots, a bike and a dog. It is not this machine, and it is not a pressure washer in the sense this page means.
• You already own this pump. Add a 5.0Ah 18V pack. Another OC 6-18 is a duplicate.

Kärcher OC 6-18 Premium

The Kärcher tank trolley

• Buy: Kärcher OC 6-18 Premium £229.99 bare. Battery separately around £58. Some centre listings from about £229 to £300
• Pressure: 24 bar, medium-pressure. Not a K2. Not a K4
• Flow: 200 L/h
• Battery: 18V Battery Power, the 18V Battery Universe packs. Sold separately on the bare listing. Around £58
• Water: 12 L trolley tank, or a tap. Optional suction hose sold separately
• Weight: 5.7 kg without accessories. About 18 to 20 kg with a full tank and the 2.5Ah pack
• Runtime: up to 12 minutes on 2.5Ah, 24 minutes on 5.0Ah
• Who it is for: Kärcher 18V owners, a front garden with no outdoor tap, a car park, a pitch, and anyone who wants a branded trolley for bikes, toys, camping kit and garden furniture

Kärcher does not currently push a widely stocked high-pressure battery K-series washer in the UK. The OC 6-18 is the cordless trolley you can actually buy here. It is a medium-pressure cleaner, not a mains K4. Twenty-four bar sits a little above a Fontus and a long way below a tap-fed K4. Kärcher says the 12 litre tank is enough for three to five dirty bikes on one fill. That is a manufacturer claim, not a count from this site. It is a believable bike figure. It is tight for a car.

The trolley is the product. Large wheels, telescopic handle, gun and lance clip on for the walk from the kitchen tap to the pitch. You fill it indoors. You roll it to the work. You are not dragging a hose through the house. That is the only reason to spend this money. If a tap is already next to the job, you can run it without the tank. Pressure and flow stay the same. You only stop walking back to refill.

Bare or Battery Set

Buy the bare trolley if you already own Kärcher 18V Battery Universe packs. Amazon has the OC 6-18 Premium at £229.99 as a bare listing. A matching 18V pack is around £58 extra if the shelf is empty. A 2.5Ah pack is a bike-and-boots battery. A 5.0Ah pack is the one if chairs or a car join the job.

The official Battery Set is part 1.328-522.0, Trafalgar code K1328522. Kärcher centres have listed that carton with a 2.5Ah pack and a charger. Some centre and comparison listings sit from about £229 to £300. Confirm what is in the carton. A Battery Set that actually includes the 2.5Ah pack is the honest first buy if you have no 18V packs. A listing that says Premium and shows a trolley with no pack is the bare tool. Shop the contents list.

Shop the live total, not the word kit. The buy button on this page is: Check latest price.

Pressure and the tank

24 bar is a strong hose, not a K2. A garden hose is about 2 to 4 bar, so this is still a real step up. It will lift dried mud from a downtube or road film from a bumper if you foam or brush first. It is more than you should put into a bike hub, a headset or an e-bike battery bay. Stand back. Use a wide fan. Keep the lance moving.

It will not pretend to be a 110 bar K2, and it will not pretend to be a 130 bar K4. Flow is 200 L/h. A K2 Home is 360 L/h. A K4 Flex is 420 L/h. Those litres rinse shampoo and stone cleaner. This trolley rinses a frame, a set of chairs and a careful car. Treat the yellow badge as branding. Shop the 24 bar figure, the 12 litre tank and the 12-minute runtime on a 2.5Ah pack.

Twelve litres is the useful household tank size, next to 15 litres on a Fontus. Kärcher’s three-to-five-bike claim is the right scale. A dirty family hatchback drinks water. Snow foam, mitt, rinse. Twelve litres will not get you through foam and rinse and a second pass on the wheels. Plan on a refill, or clip the inlet to a tap if one is there. Foam first, rinse with purpose. Do not hold the trigger while you stand and look.

A bike is an open frame. Paint on a car is a sealed skin. Both want a wide fan and distance. Stand 30 cm or more from a frame. Further is safer on lacquer. Soap is a low-pressure job: a mitt or a brush, then a fan rinse. Bike and paint notes sit on the bikes page. First-use nozzle order is on the how-to page.

Battery and runtime

The platform is Kärcher 18V Battery Power, the 18V side of the Battery Universe. One family across the yellow garden tools. That is the reason to buy this trolley if the packs are already on the shelf. It is also the reason to skip it if the packs on the shelf are Bosch, Ryobi or Worx. A bargain tool that needs a new charger and two packs is not a bargain.

Kärcher quotes up to 12 minutes on a 2.5Ah pack and 24 minutes on a 5.0Ah pack. That is battery time. The 12 litre tank will not outlast a long wash either. Twelve minutes is enough for furniture or a couple of bikes. It is not enough for a leisurely car wash. If you already own a 5.0Ah 18V Kärcher battery, use that. A second pack is the practical answer, not a wish that the pump would sip less. A 2.5Ah pack will do the bikes and then ask for a rest.

Foam jet and wash brush are extras. They are not in the carton. If you wash a car, buy the foam jet rather than hoping 24 bar will shift road film on its own. The SmartBrush idea on a Fontus is the same job: pressure alone will not do everything. Use a brush on wheels and frames. Leave a pencil jet off paint.

Water: tank or tap

The OC 6-18 carries 12 litres. That is the point and the limit. Fill it at the kitchen tap. Roll it to the front garden, the car park or the pitch. You are not fetching a bucket as a second object. You are not dragging a hose through the hall. When a tap is next to the work, clip the inlet on and forget the tank. Unlimited water, still no 13A lead.

The suction hose that would let you draw from a bucket or a water butt is extra. That is a poor omission if you wanted both a tank and a fallback. The handhelds on the cordless guide include a siphon in the carton. This trolley does not. If bucket-draw is the job you actually have, you bought the wrong shape.

Use clean water. Sand in a pump is a new trolley. Fill from the kitchen tap if the water butt is green. You refill the tank. You do not get 15 litres for this money, and you do not get 50. If 12 litres feels small before you have bought it, the Fontus is the larger household tank and the Makita case is the van-sized one. Both sit on the tank page.

A tap feed does not turn this into a mains washer. Pressure and flow stay the same. You only stop walking back to the kitchen. That is useful on a hatchback. It is not a reason to skip a K4 if the tap and the socket are already there and the Saturday includes chairs and a small car every week.

Weight and daily use

5.7 kg without accessories. About 18 to 20 kg with a full tank and the 2.5Ah pack. Add one kilogram per litre to the empty weight. The wheels exist for that reason. You will roll it. You will not carry it up a flight of stairs with the tank full. Drain it before the boot. A 1.5 kg handheld lives next to a helmet. This one lives in the shed.

That is why it wins when the water is the problem, and loses when the job is one bike next to a water butt. An 18 kg trolley does not live in a backpack. If you cannot roll 20 kg over a gravel strip, this is the wrong shape for your front garden, however tidy the tank looks on paper.

After the job, run the pump on clean water if you have been in a dirty tank. Drain what you can before frost. A trolley still holds water in the head and the tank. The how-to page has the drain-down habit for any washer you will leave in a shed. Empty the tank. Do not store it full and hope.

Not the OC 3

Do not mix this up with the OC 3 family. The current UK rinser is the OC 3 Foldable, an 8 litre foldable jug at about 5 bar. The older OC 3 Plus was a 7 litre version of the same idea. Fine for muddy boots and a dog after a walk. They are not pressure washers in the sense this page means, and they are not a cheaper OC 6-18.

The OC 4 Multijet is the same low-pressure job with an 8 litre tank. Not a pick. If you landed here because a tile said Outdoor Cleaner and showed a yellow jug, check the number. OC 6-18 is the medium-pressure trolley. OC 3 is a rinse.

Which carton

1. You already own Kärcher 18V Battery Universe packs. Bare trolley at £229.99. Use a 5.0Ah pack if the job is more than a couple of bikes.
2. You own no Kärcher batteries. Confirm a Battery Set carton, or add a pack at around £58. The 2.5Ah pack is short. A 5.0Ah pack is the one that makes a car rinse less stop-start.
3. You already own this trolley. A spare 5.0Ah pack. Not a second OC 6-18.
4. You already live on Bosch, Ryobi or Worx. Do not start another family for 24 bar. Read the tank page or the cordless guide and stay on the packs you have.

There is only one OC 6-18 Premium we will send you to. Shop the Premium trolley, 12 litres, 24 bar, 18V Battery Power. Confirm whether a pack is in the box. A listing that only shows a foldable jug is an OC 3.

Not a mains substitute

A cordless tank is for the job where the lead and the garden hose are more hassle than the dirt, and you will not carry a bucket. It is not the household washer. 24 bar and 200 L/h will not do a green drive. The tank runs out before the slabs do. If the Saturday is cars and a normal patio, and the tap and the socket are there, buy mains. A K4 is the usual house buy on the Kärcher hub when you can spend about £200.

The Fontus is the other named household tank. It is not a pick on this page. Fifteen litres, 20 bar, from £179 bare or about £198 as a kit. That deep page is the Bosch Fontus review. A handheld Worx, Ryobi or Greenworks is a siphon gun, not an OC 6-18 with the tank sawn off. That class sits on the cordless guide. A Makita DHW080ZK is a 50 litre, 55 bar case for people already deep in LXT. That comparison stays on the tank page.

FAQ

Is the Kärcher OC 6-18 worth it?

Yes, if there is no outdoor tap, you refuse a bucket, and you already run 18V Battery Universe packs or you will buy one. Yes, if the job is bikes, furniture and a careful rinse, and you will fill the trolley at the kitchen sink. No, if you have a tap and a socket and you will wash a patio. At £229.99 bare it is the Kärcher tank you can actually buy. Add about £58 if you have no pack. A centre listing at £300 is only worth it if that is the live street and you still want this platform.

Does it come with a battery?

Often not. The Amazon street listing is £229.99 bare. A matching 18V pack is around £58. The official Battery Set, part 1.328-522.0, may include a 2.5Ah pack and a charger. Some Kärcher centre listings sit from about £229 to £300. Shop the contents list and the live total. There is one button on this page for both.

Is 24 bar enough?

For a bike, chairs and a careful rinse, yes, if you foam or brush first. For road film on a weekly family car, or for moss on slabs, no. A garden hose is about 2 to 4 bar, so 24 bar is still a real step up. A Fontus is 20 bar. A K2 is 110 bar. A K4 is 130 bar. Shop the job, not the yellow badge on a neighbouring tile.

Is it a Kärcher K4?

No. It is a medium-pressure outdoor cleaner with a 12 litre tank. A K4 Power Control Flex is a 130 bar, 420 L/h mains machine. They share a badge. They do not share a job. If you have a tap and a socket, buy the K4. If you do not, stay here or read the tank page.

Can the OC 6-18 wash a car?

Yes, if you treat it as a wash, not a blast. Foam or shampoo, mitt, then a fan rinse. Twelve litres and 12 minutes on a 2.5Ah pack is a careful hatchback with a refill, not a weekly fleet. A 5.0Ah pack helps. A tap hook-up helps. None of that replaces a mains washer for a family that washes every weekend. Paint notes sit on the bikes page. This trolley is still 24 bar.

Can it do a patio?

A small, lightly dirty patch, if you accept a slow job, a refill and a battery swap. A green terrace, driveway oil or a full set of slabs wants a mains machine in the 130 bar class. Cordless water volume and runtime are the limit, not just bar. Do not buy this as a patio washer and hope.

Do I need a tap?

You need a tap to fill the tank. You do not need an outdoor tap next to the work. That is why this trolley exists. Fill it at the kitchen mixer. Roll it outside. A K4 without an outdoor tap is a box in the kitchen. An OC 6-18 without water in the tank is a dry motor. If you will carry a bucket instead, a handheld on the cordless guide is the cheaper path.

How long does the battery last?

Up to 12 minutes on a 2.5Ah pack and 24 minutes on a 5.0Ah pack, on Kärcher figures. That is battery time, not tank time. At 200 L/h the 12 litre tank is a few minutes of trigger time as well. Plan the job around a couple of dirty bikes or a rinsed car with a refill, not an afternoon on the drive. Swap packs. Do not stand there waiting for a charger to refill a cell between arches.

OC 6-18 or Bosch Fontus?

OC 6-18 if the 18V Battery Universe packs are already on the shelf, or you want the Kärcher trolley and 24 bar. Fontus if you are starting from no Kärcher batteries and you want 15 litres and a cheaper complete kit. That deep page is the Bosch Fontus review. The class argument stays on the tank page. This page will not re-shortlist the Fontus.

Is the OC 3 the same machine?

No. The OC 3, OC 3 Plus and OC 3 Foldable are 5 to 6 bar jugs. Useful for boots, a bike and a dog. Not useful for road film on a car, and not a substitute for the OC 6-18. If a tile says Outdoor Cleaner, read the number on the carton.

More reading

The tank class in full is the cordless pressure washer with tank guide. The bigger household tank is the Bosch Fontus review. Handhelds sit on the cordless guide. Bikes as a job sit on the bikes page. The yellow mains range sits on the Kärcher hub. First use and frost drain-down are on how to use a pressure washer.