Hiboy S2 MAX vs NIU KQi3 Pro: Which Should You Buy? (2026)

Side by side

	Hiboy S2 MAX 62	NIU KQi3 Pro 44
Motor & speed
Top speed (claimed)	19 mph	19.9 mph✓
Peak power	650 W	700 W✓
Nominal power	500 W✓	350 W
Drive	Single motor	Single motor
Max incline	36.4%✓	20%
Battery & range
Claimed range	40 mi✓	31 mi
Est. real-world range	22–28 mi✓	17–22 mi
Battery	557 Wh✓	486 Wh
Charge time	6.5 h	6 h✓
Build
Weight	40 lb✓	44.75 lb
Max load	220 lb	265 lb✓
Suspension	—	none
Brakes	—	Dual disc front & rear + regenerative
Water resistance	IPX4	IP54
Tyres	10" tubeless	9.5" pneumatic
Features
Score (within category)	62/100✓	44/100
Price	$490	$330✓

A green ✓ marks the better figure on that row. “—” means the manufacturer does not publish it; a blank is never counted as a loss. Scores compare each model within its own category.

What the makers don't publish

Hiboy does not publish suspension and brake hardware for the Hiboy S2 MAX — 2 of the 15 specifications we track. NIU does not publish system voltage for the NIU KQi3 Pro — 1 of the 15 specifications we track. We show a dash for each of those rather than estimate, and a missing figure is never counted against a scooter in our scoring — the component is dropped and the remaining weights renormalise. Because both sheets have holes, several rows of the table above cannot be compared at all, so treat this as a comparison of what is published rather than a complete picture. If one of the unpublished figures is the one your decision turns on, ask the seller in writing before you buy: a maker that measures a specification usually states it, and silence is a reasonable prompt to look harder.

Motor & speed

On top speed the two are effectively level — 19 mph plays 19.9 mph — so speed alone will not decide this, and you should weigh the other rows more heavily. The NIU KQi3 Pro carries more motor on paper, and that surplus shows up in acceleration and on climbs rather than in a higher cruising speed — the place a stronger motor actually earns its keep is the hill you take twice a day. The Hiboy S2 MAX also claims the steeper hill-climbing grade, worth noting if your commute has a real gradient rather than a gentle rise. Read any top-speed figure as a maximum reached under ideal conditions; rider weight and gradient both pull it down in the real world, so treat these numbers as a ceiling rather than a cruising promise.

Battery & range

Battery capacity is the honest way to compare range, because watt-hours cannot be marketed around: the S2 MAX holds 557 Wh and the KQi3 Pro 486 Wh. The Hiboy S2 MAX's 15% larger pack will out-last the other on the same route whatever the two brochures claim, and it is the single number to trust most in this section. Both claims deserve the usual discount. The S2 MAX's 40-mile figure realistically works out to about 22–28 miles once you account for a normal rider at real speeds; the KQi3 Pro's 31 lands at roughly 17–22. Plan around the lower end of whichever band matters to you: if your daily round trip does not fit inside it with margin to spare, the range difference here is the deciding factor and you should pick the bigger battery. Whichever you choose, remember that both figures assume a fresh battery; a pack loses roughly 20–30% of its capacity after a couple of years of daily cycling, so a used example of either will fall short of these numbers.

Build & ride

Weight is where the daily reality lives: 40 lb against 44.8 lb, a 4.8 lb difference. If you carry the scooter up stairs or onto a train, the lighter Hiboy S2 MAX is the one you will actually keep using — the difference between a scooter that gets ridden and one that gathers dust is often a single flight of steps. Each publishes a water-resistance rating (IPX4 and IP54); the higher of the two shrugs off heavier rain, though neither should be ridden through standing water or pressure-washed. Tyres differ too: S2 MAX runs tubeless and KQi3 Pro pneumatic. Pneumatic and tubeless tyres absorb more of the road than solid ones, at the cost of the occasional puncture; solid tyres never flat but pass more buzz into your hands and feet.

Price, score & value

The NIU KQi3 Pro is the cheaper of the two, $330 against $490 — a $160 gap. Whether that gap is worth closing depends entirely on whether the pricier scooter's advantages above line up with your priorities. Within their category the Hiboy S2 MAX scores higher (62/100 to 44/100). Remember that our scores are within-category judgements — this comparison is only meaningful because both sit in the same or an adjacent class. If value per dollar is your lens, use the cost-of-ownership calculator on this site: a slightly cheaper scooter with pneumatic tyres can cost more to run over a few years than a pricier one on solid tyres, and the sticker price alone hides that.

What the extra $160 buys

What these numbers actually govern

Here is what each of these measures controls in general — both the ones that separate these two and the ones they share. These describe the measure, not a claim about how either scooter rides, which we have not tested.

max incline

A climbing grade is quoted under test conditions; a heavier rider reaches the limit sooner than the published figure suggests.

price

Price is the one figure that is not a specification — it moves with stock and promotions, so treat any gap as current rather than permanent.

nominal power

Nominal power describes sustained output: it shows up in acceleration and in holding speed on a long climb rather than in a higher top speed.

claimed range

Every claimed range figure is measured at a light rider weight, a low constant speed and on flat ground, which is why we show a computed real-world band beside it.

max load

A load rating covers rider plus cargo, not the rider alone — a backpack and a week's shopping come out of the same allowance.

Drive (both Single motor)identical on both

A second motor adds traction and acceleration at the cost of weight and battery drain. Where both use the same arrangement, drive layout is not a separator.

Price & where to buy

Who should buy which

Buy the Hiboy S2 MAX if your route has a real gradient (36.4% vs 20% claimed grade), or you want more sustained power (500 W vs 350 W — a decisive 30% edge). Buy the NIU KQi3 Pro if you want to spend less ($330 vs $490), or you or your cargo need the higher weight limit (265 lb vs 220 lb). Whichever you pick, 1 specification are identical across both — drive — so those rows cannot decide it. Within their category our score puts the Hiboy S2 MAX at 62/100 against 44/100.

Bottom line: the Hiboy S2 MAX is the safer default here — it claims a steeper grade (36.4% vs 20%). The NIU KQi3 Pro earns its place if less ($330 vs $490) matters more to you. Every figure here is the manufacturer's published claim or a value we compute from it, linked back to each maker's own specification so you can check it yourself.

Frequently asked questions