Dreame L40s Ultra

The Dreame L40s Ultra sits at an interesting crossroads: it packs flagship-level cleaning power and a seriously impressive self-maintaining dock, yet it often sells for hundreds less than competitors with similar capabilities. Whether that trade-off makes sense depends largely on what you prioritize in a robot vacuum.

Release and Pricing

Dreame unveiled the L40s Ultra globally around May 2024, with U.S. availability by late summer and a European rollout in spring 2025. The official price sits at $1,399.99, but aggressive launch promotions and holiday sales have frequently dropped it to the $800-$1,100 range. At those prices, it undercuts rivals like the Roborock S8 Pro Ultra and Ecovacs X2 Omni while matching or exceeding many of their specs.

The L40s comes in black or white finishes and is sold through Dreame’s website and Amazon. A word of caution: gray-market imports exist, and Dreame implements region-locking on some models. Units labeled “L40s Pro Ultra” in certain regions may have different firmware or limited support. Stick with authorized sellers to ensure you get the full three-year U.S. warranty.

Three variants exist in the L40s lineup: the Ultra (reviewed here), the Ultra AE, and the Ultra CE. The Ultra represents the top tier with maximum suction and the most advanced features. The AE shares the 19kPa suction but includes an RGB camera for better obstacle detection. The CE is the budget option with 13kPa suction and a simpler base station.

Physical Design

The robot measures 350mm in diameter and 97mm tall according to official specs, though the LiDAR turret pushes the actual height closer to 105mm (about 4.1 inches). At roughly 4.1kg (9 lbs), it’s average weight for a high-end unit.

The docking station is substantial: 340 x 457 x 590mm (roughly 13.4” x 18” x 23.2”) and about 9kg. You’ll need dedicated floor space for it, but that bulk houses impressive functionality.

Build quality feels solid throughout. The glossy plastic finish shows no loose parts, and the overall construction matches what you’d expect from a $1,400 robot. The design has matured from earlier Dreame models with no reports of brittle parts or water leakage.

Suction and Cleaning Power

The headline spec is 19,000 Pa maximum suction from the TurboForce 6.0 motor. For context, that’s nearly double what most Roborock flagships offer. Independent testing measured about 21 CFM of airflow with sealed suction around 0.86 kPa at the brush inlet, confirming the strong performance claims.

Four suction levels are available: Quiet, Standard, Turbo, and Max+. The 19kPa figure represents peak power in Max+ mode, which the robot uses selectively on carpets or heavily soiled areas. Even lower settings handle most cleaning tasks effectively.

The DuoBrush System

One of the L40s Ultra’s standout features is the HyperStream Detangling DuoBrush. This dual-material roller combines soft bristles for sweeping fine dust from crevices with TPU rubber fins that beat dirt out of carpet fibers. The design virtually eliminates hair tangling.

In testing, even long strands (10-12 inches) get picked up without wrapping around the roller. Vacuum Wars gave it high marks for pet hair handling, and Dreame’s TUV-certified claim of 99.99% hair removal with zero tangles holds up in practice. The brush is spring-loaded and self-adjusting to maintain contact on uneven floors.

A TriCut brush (different bristle pattern for cutting hair) is available separately if you prefer it, though the DuoBrush comes standard on the Ultra model.

Smart Side Brush

The single side sweeper isn’t ordinary. It adjusts height automatically, lifting out of the way on carpets or during mop-only passes. More notably, it extends outward to reach debris in corners and along edges. This telescoping arm reaches about 2cm further than a standard fixed brush, grabbing dirt from wall-floor junctions that round robots typically miss.

The side brush also adjusts speed, slowing near edges to prevent flicking debris away. Both the main and side brushes can lift completely, an unusual level of engineering detail that makes a real difference in cleaning versatility.

Dustbin and Filtration

The onboard dustbin holds approximately 310ml, smaller than some competitors. However, the auto-empty dock dumps debris after each run (or even mid-run when returning for mop cleaning), making the modest capacity irrelevant in practice.

Filtration uses a triple-layer system with an H11-class filter. That’s not certified HEPA (H13), but captures roughly 95-99% of common dust particles. The filter is washable and should be replaced annually. For most homes, this filtration level is more than adequate.

Battery Life

The 5,200 mAh battery delivers up to 180 minutes in Quiet mode on hard floors. Real-world mixed use (vacuuming and mopping with standard power) typically yields 140-160 minutes. One reviewer covered 1,800 square feet with battery to spare.

If the battery runs low mid-job, the robot returns to dock, charges, then continues where it left off. The dock includes fast charging that’s about 30% quicker than previous Dreame models, reaching full charge in approximately four hours.

Navigation

A dToF LiDAR sensor handles mapping and navigation. The spinning laser turret creates accurate floor maps and plans efficient cleaning paths even in complete darkness. You can save up to four maps for multi-level homes.

Map accuracy is excellent. Users consistently report the app-generated layouts closely match their actual floor plans, and the robot respects no-go zones reliably. Initial mapping typically completes in under ten minutes.

Some early firmware versions showed occasional navigation quirks, with the robot sometimes taking inefficient paths in CleanGenius AI mode. Updates have largely addressed these issues, though switching to standard room-by-room cleaning mode can yield more predictable behavior if problems persist.

Obstacle Avoidance

Here’s where the L40s Ultra makes a notable trade-off. Unlike many flagship robots, it lacks an RGB camera. Instead, it uses a 3D structured light sensor (infrared-based) to detect obstacles. This works in total darkness and doesn’t raise privacy concerns about cameras in your home.

The downside: without visual recognition, the robot identifies objects by shape rather than type. It can’t distinguish between a sock and pet waste. In Vacuum Wars testing, the Ultra scored just 7 out of 24 on their obstacle course. The Ultra AE (which has a camera) scored 19 out of 24.

In practice, the L40s Ultra will navigate around larger obstacles like shoes, toys, and pet bowls. It struggles with thin or small objects like charging cables. Pet waste avoidance is not reliable. Pet owners should clear any accidents before running the robot.

The robot does include standard cliff sensors, wall-tracking sensors, and carpet detection. It won’t fall down stairs and can automatically lift mops and boost suction when transitioning to carpet.

Threshold Climbing

The EasyLeap system uses four-wheel drive with two auxiliary front wheels to climb obstacles. The robot handles thresholds up to 22mm (0.87 inches) in a single step, and up to 40mm if the rise is split into two stages. Most interior thresholds fall well under 20mm, so this capability exceeds typical needs.

Thick rugs, sliding door tracks, and uneven flooring that strand other robots pose no problem here.

Noise Levels

Operating noise sits around 55 dB in Quiet mode (comparable to a running refrigerator) and climbs to the low 60s in Standard mode. Maximum suction peaks around 67-72 dB right at the robot. The auto-empty cycle is the loudest event at roughly 68-80 dB, but it lasts only 10-15 seconds.

For apartment living or nighttime cleaning, the Quiet mode is genuinely unobtrusive. Pets typically aren’t bothered by the gentle hum.

Mopping System

Two circular spinning pads at the rear rotate rapidly to scrub floors. The pads press down with motorized force and spin in opposite directions for effective scrubbing action. The robot can vacuum and mop simultaneously or run dedicated passes for each task.

The Dual Flex Arm mechanism allows the mop modules to extend outward for edge cleaning and retract when not needed. They can also raise up to 10.5mm off the floor when carpet is detected, keeping most low-pile rugs dry. For thicker carpets, Dreame recommends removing the pads entirely.

Water comes from the dock’s 4.5L clean water tank, which automatically refills the robot’s small internal reservoir. One tank fill can theoretically cover 4,300 square feet of mopping. The dock can also automatically mix in cleaning solution.

Mopping Performance

The dual spinning pads handle day-to-day maintenance and sticky spills effectively. The dock washes pads with water heated to 75 degrees C (167 degrees F), helping dissolve grime. For dried spills like coffee or soda, the robot typically removes most of the stain in one pass.

Very stubborn stains may require multiple passes or manual intervention. Using medium water settings with the included cleaning solution produces good shine with minimal streaking. The mop won’t match a dedicated floor scrubber for heavily ingrained dirt, but it keeps floors visibly clean between deeper cleanings.

The pads return to the dock for automatic washing after every 20 square meters (adjustable in the app), ensuring they’re not just smearing dirty water around.

The PowerDock

The docking station handles eight functions automatically: charging, emptying the dustbin into a sealed bag, refilling the robot’s water, washing the mop pads with hot water, drying the pads with warm air, self-cleaning its internal components, dispensing cleaning solution, and providing faster charging.

Auto-Emptying: The 3.2L dust bag holds roughly 60-100 days of dirt depending on your home. The strong suction pulls debris (and even fine dust from the filter) into a sealed bag that closes when removed. No dust plume, minimal contact with collected dirt. Bags cost about $3-5 each.

Mop Washing: A textured washboard scrubs the spinning pads while the dock pumps warm water (up to 75 degrees C) over them. After scrubbing, the dirty water gets sucked into a separate 4.0L tank. Dreame claims 99% stain removal from pads.

Drying: Built-in heater and fan dry the pads after cleaning, preventing mildew and odor. Pads emerge only slightly damp or fully dry with no musty smell.

Water Tanks: The generous 4.5L clean water and 4.0L dirty water tanks mean refilling/emptying roughly every 30 days under typical use. These are larger than most competitors.

Software and App

The Dreamehome app (iOS and Android) provides comprehensive control. Initial setup is straightforward: scan a QR code, connect to 2.4 GHz Wi-Fi, and the robot maps your home during its first run.

The app lets you edit maps extensively: split or merge rooms, name spaces, set different cleaning modes per room, and create no-go or no-mop zones. Scheduling options are granular, supporting multi-room selection and different modes per schedule.

CleanGenius mode uses AI to decide when to vacuum versus mop and adjusts suction automatically. Some users find this mode unpredictable and prefer setting custom routines (vacuum then mop, specific rooms, etc.) for more consistent results.

Voice control works through Amazon Alexa, Google Assistant, and Siri Shortcuts. The robot lacks a built-in microphone, so all voice commands go through your smart speaker or phone.

Since there’s no camera, the app doesn’t offer live video streaming or remote driving. Privacy-conscious buyers may appreciate that the robot captures no images of your home.

Maintenance and Consumables

Day-to-day maintenance is minimal. Empty the dirty water tank weekly, refill clean water as needed, and replace the dust bag every 2-3 months. The dock reminds you when attention is needed.

Periodic tasks include checking the main brush for hair (though tangles are rare), cleaning the side brush shaft, and wiping sensors. The filter should be tapped clean regularly and replaced annually.

Estimated annual costs:

• Dust bags (4 per year): ~$20
• Filter replacement: ~$15
• Mop pads (if replaced): ~$20
• Cleaning solution: ~$10-20

Total ongoing cost runs about $60-70 per year for consumables.

Warranty and Support

U.S. buyers get a three-year warranty, significantly longer than the industry-standard one year. Extended warranties (+1 year for $69, +2 years for $139) are available for purchase.

Support responsiveness has been mixed. Initial contact often reaches scripted responses or chatbots. Persistence usually leads to resolution. Dreame maintains an active presence on Reddit (r/Dreame_Tech) where company representatives have stepped in to help users with issues.

Cleaning Performance

Hard Floors: Near-perfect dust and crumb pickup in testing. The combination of strong suction, effective brush design, and mopping leaves floors visibly spotless. Edge cleaning is excellent for a round robot thanks to the extending side brush and mop arms.

Carpet: The L40s Ultra scored 92% on deep carpet cleaning tests (embedded sand removal), ranking among the top performers. The automatic suction boost on carpet and effective brush agitation pull out ingrained debris. Performance on high-pile shag carpet suffers, as with all robot vacuums.

Pet Hair: Excellent pickup with virtually no tangling. Testing showed 91% removal of pressed-in dog hair from carpet. The mop also helps capture hair that sticks to hard floors from static.

Edge and Corner Cleaning: The extending side brush and mop arms get closer to walls than typical round robots. Corners still see small triangular areas the round shape can’t reach, but overall edge performance is above average.

Pet Owner Considerations

The L40s Ultra handles pet hair exceptionally well. Daily runs keep shedding under control far better than weekly manual vacuuming. The anti-tangle brush means you’re not constantly cutting hair off the roller.

Cat litter, kibble, and pet food crumbs are no problem. The mop wipes up paw prints and water bowl drips.

The critical caveat: no reliable pet waste avoidance. Without a camera, the robot can’t identify pet accidents. If it encounters waste, it will spread it. Pet owners should clear any accidents before running the robot or schedule runs when they can supervise.

Noise levels are low enough that most pets aren’t bothered. The methodical movement pattern is less startling than older random-pattern robots.

Home Compatibility

Home Size: With up to 180 minutes of runtime and recharge-and-resume capability, the L40s Ultra handles homes over 3,000 square feet. Smaller spaces obviously pose no challenge.

Floor Types: Works well on hardwood, tile, vinyl, laminate, and low-to-medium pile carpet. High-pile shag should be marked as a no-go zone or cleaned separately with mops removed.

Furniture Clearance: The 4.1-inch height fits under most beds and sofas. Furniture with less than 4.2 inches of clearance should be blocked in the app to prevent the robot from wedging underneath.

Mixed Floors: The automatic mop lifting and carpet detection handle transitions smoothly. Low-pile rugs stay dry during vacuum-and-mop runs.

How It Compares

Against the Roborock S8 Pro Ultra (~$1,199-$1,399): Similar overall capability, but Roborock has better obstacle avoidance with its AI camera and proven poop detection. Dreame has higher suction, a longer warranty, and larger water tanks. The S8 Pro often costs $100-200 more.

Against the Ecovacs X2 Omni (~$1,499): The X2’s square shape provides genuinely superior corner cleaning. It also has strong AI-based obstacle avoidance. Dreame counters with higher suction, larger tanks, longer warranty, and lower price.

The L40s Ultra represents excellent value, delivering 90-95% of what competitors offer at a meaningfully lower price point, especially during sales.

Known Limitations

Navigation quirks: Early firmware showed occasional inefficient pathing in CleanGenius mode. Updates have improved this, but switching to manual room selection provides more predictable behavior.

Obstacle avoidance gaps: Without an RGB camera, it will hit thin cables and miss small objects. The infrared sensor works for larger obstacles but isn’t foolproof.

Mop clearance on thick carpet: The 10.5mm lift handles low-pile rugs but may still contact medium-pile fibers. Set no-mop zones for thicker carpets.

No pet waste detection: This bears repeating. Clear accidents before running the robot.

Loud auto-empty: The 10-15 second emptying cycle hits about 80 dB. Brief but noticeable.

Large dock: Plan for dedicated floor space roughly 14” x 18” for the station.

The Bottom Line

The Dreame L40s Ultra delivers flagship cleaning performance and genuine hands-off convenience. Its suction power ranks among the highest available, the anti-tangle brush handles pet hair brilliantly, and the self-maintaining dock means weeks can pass between manual interventions.

The trade-off is obstacle avoidance. Without a camera, it handles large obstacles well but misses cables and can’t identify specific hazards like pet waste. If your home has frequent floor clutter or unreliable pets, the Ultra AE (with camera) or a competitor like the Roborock S8 Pro Ultra might be safer choices.

For buyers who can manage minor floor prep and don’t need guaranteed pet waste detection, the L40s Ultra offers exceptional value. The three-year warranty provides peace of mind, and sale prices often drop it well below similarly capable competitors. It’s one of the strongest options in the premium robot vacuum segment for 2025.