The best robot pool cleaner for a large pool, by pool length
For a pool longer than 40 feet, buy the Dolphin Nautilus CC Supreme ($1,449). Maytronics rates it for in-ground pools up to 50 feet, and it runs on a cord, so it never runs out of battery halfway through a big pool. If your pool is 40 feet long or shorter, the Dolphin Nautilus CC Plus ($829) is rated for it and costs less.
Want cordless? Buy the Beatbot AquaSense 2 Ultra ($2,299). Beatbot says one cleaning cycle covers up to 3,444 sq ft of pool.
Pool up to 50 feet
Dolphin Nautilus CC Supreme
Corded. Maytronics rates it for in-ground pools up to 50 feet, and it scrubs the waterline. No CPSC recall names it.
Pool up to 40 feet
Corded. Maytronics rates it for in-ground pools up to 40 feet. It costs less, but it does not scrub the waterline.
If it must be cordless
Beatbot AquaSense 2 Ultra
Cordless. Beatbot says one cleaning cycle covers up to 3,444 sq ft of pool. It is heavy: 29 lb dry.
Is my pool large?
The Pool Nerd counts a pool longer than about 30 to 33 feet as large. (The Pool Nerd)
Makers rate the two kinds of robot differently. A corded robot is rated by the longest pool it can clean. A cordless robot is rated by how much pool it can clean on one charge, in square feet.
To get your pool’s floor area, multiply its length by its width. A 20 by 40 foot pool has 800 sq ft of floor. A 25 by 50 foot pool has 1,250 sq ft. Walls and steps add more.
The picks side by side
Rated sizes and runtimes are each maker’s own. Prices are Amazon’s on November 2, 2026.
| Dolphin Nautilus CC Supreme | Dolphin Nautilus CC Plus | Dolphin Explorer E50 | Beatbot AquaSense 2 Ultra | |
|---|---|---|---|---|
| Price | $1,449 | $829 | $1,629 | $2,299 |
| Cord | Corded | Corded | Corded | Cordless |
| Rated pool size (maker) | 50 ft long | 40 ft long | 50 ft long | 3,875 sq ft (one cycle: 3,444) |
| Pools | In-ground | In-ground | In-ground and above-ground | In-ground and above-ground |
| Runtime (maker) | 2.5 hours a cycle | 2 hours a cycle | 2 hours a cycle | Up to 5 hours (Beatbot) |
No CPSC recall names the CC Supreme, the CC Plus, the Explorer E50, or the AquaSense 2 Ultra, as of November 2, 2026.
Pool up to 50 feet: Dolphin Nautilus CC Supreme
Why: Maytronics rates it for in-ground pools up to 50 feet (Maytronics: Nautilus CC Supreme). It plugs into a power supply beside the pool, so a big pool never outlasts the battery. It scrubs the waterline as well as the floor and walls.
The Pool Nerd’s top pick for large pools is the Dolphin Premier (The Pool Nerd). We lead with the CC Supreme because it is rated for 50 feet and sells on Amazon for $1,449.
A large above-ground pool: Dolphin Explorer E50
Maytronics rates it for pools up to 50 feet (Maytronics: Explorer E50), and lists it for above-ground pools as well as in-ground ones. It costs $1,629.
Before you buy a corded robot
Measure from the outlet where the power supply will sit to the far corner of your pool. The robot’s cable has to reach it. Each maker lists the cable length on its spec sheet. If your pool is longer than 50 feet, none of these picks is rated for it.
Pool up to 40 feet: Dolphin Nautilus CC Plus
Why: Maytronics rates it for in-ground pools up to 40 feet (Maytronics: Nautilus CC Plus), and it costs $620 less than the CC Supreme. It does not scrub the waterline.
Can a cordless robot clean a big pool?
PCWorld says most makers overstate how much pool a cordless robot covers on one charge (PCWorld: best robot pool cleaners). In its test, the Wybot S2 ran about 2 hours 45 minutes, short of the promised 3.5 hours (PCWorld: Wybot S2 review). The Pool Nerd advises against a cordless robot for a large pool (The Pool Nerd).
If it must be cordless, buy the Beatbot AquaSense 2 Ultra ($2,299). Beatbot recommends it for pools up to 3,875 sq ft, and says one cleaning cycle covers up to 3,444 sq ft (Beatbot: AquaSense 2 Ultra). In PCWorld’s test it ran for about 6 hours (PCWorld: AquaSense 2 Ultra review). When it is done it floats against the wall for about 15 minutes (PCWorld: AquaSense 2 Ultra review). It weighs 29 lb, and up to 45 lb when you lift it out full of water (PCWorld: AquaSense 2 Ultra review).
How we checked
Each rated size is quoted from the maker’s own page and re-read every night. We searched the CPSC recall list for Maytronics, Dolphin and Beatbot; the last check was November 2, 2026. Want a cordless robot for an average-size pool? See the best cordless robotic pool cleaners.
Questions
What counts as a large pool for a robot?
The Pool Nerd counts a pool longer than about 30 to 33 feet as large. Corded robots are rated by pool length, so check that the rating is at least as long as your pool.
How do I work out my pool's floor area?
Multiply its length by its width. A 20 by 40 foot pool has 800 sq ft of floor; a 25 by 50 foot pool has 1,250 sq ft. Walls and steps add more.
Can a cordless robot clean a 50-foot pool?
Some are rated for it. In PCWorld's tests, one cordless robot ran well short of its claim and another ran longer. For a pool that long, a corded robot rated for 50 feet is the surer bet to finish in one run.
Sources
Each maker’s own pages, the testers named above, and the CPSC recall list (checked November 2, 2026). Amazon prices from Amazon’s product data on November 2, 2026. How we work.
- Maytronics: Nautilus CC Plus
- Maytronics: Nautilus CC Supreme
- Maytronics: Explorer E50
- Beatbot: AquaSense 2 Ultra
- PCWorld: Wybot S2 review
- PCWorld: best robot pool cleaners
- The Pool Nerd
- PCWorld: AquaSense 2 Ultra review
- Dolphin Nautilus CC Supreme: maker’s page
- Dolphin Nautilus CC Plus: maker’s page
- Dolphin Explorer E50: maker’s page
- Beatbot AquaSense 2 Ultra: maker’s page
Next: Best robotic pool cleaner for an inground pool · for an above-ground pool · Is my robot recalled?