BetaFPV 1805

What you get

• 16.15 g

  BetaFPV weighs the 1550KV at 16.15 g and the 2550KV at 16.19 g.

  Source: BetaFPV comparison chart

• Up to 710 g

  On BetaFPV's 24 V bench the 1550KV reached 710 g on Gemfan 5125 three-blade props at 11.83 A; the 2550KV reached 694 g at 16 V and 19.20 A.

  Source: BetaFPV 1550KV sheet, BetaFPV 2550KV sheet

• Plain 1.5 mm shaft

  BetaFPV kept an unthreaded 1.5 mm shaft to save weight, so props are fixed with M2 screws rather than a nut.

  Source: BetaFPV product page

What to pair it with

Our reading of BetaFPV’s numbers, so your build matches what the motor was tested with.

ESC

BetaFPV pairs it with its F405 flight controller and 35A BLHeli_32 ESC, or its 35A AIO board. Its bench tops out at 11.83 A (1550KV, 24 V) and 19.20 A (2550KV, 16 V). (BetaFPV product page, BetaFPV 1550KV sheet, BetaFPV 2550KV sheet)

Props

BetaFPV recommends Gemfan 5125 three-blade, Gemfan 5020 and HQ 5025 three-blade props, fixed with M2 screws; its bench uses the Gemfan 5125. (BetaFPV product page, BetaFPV 1550KV sheet)

Battery

6S for the 1550KV, 4S for the 2550KV. (BetaFPV product page, BetaFPV comparison chart)

Frame

Four M2 screws on a 12 mm circle; BetaFPV recommends 4- to 5-inch frames, its TWIG ET5 toothpick frame in particular. M2 screws come in the box. (BetaFPV product page, BetaFPV 1550KV sheet)

Where to buy

• BETAFPVthe maker's store; $23.99 for four 1550KV motors, the only version in stock when checked (the 2550KV, $15.99 single or $23.99 for four, was sold out)
  $23.99seen Oct 19, 2026
  Visit

Plain links, not affiliate links. Prices change; the store’s page has the current one.

Full specs

Bench data

Redrawn from BetaFPV’s test reports. Thrust is static pull on a bench, more than you get in flight. Power is volts × amps; efficiency is thrust divided by power.

Inside the motor

A brushless outrunner: the coils stand still in the middle and the magnets spin around them. From the top down:

• Bell. Blue anodised; the top is dark with four blue spokes in an X, and four M2 prop holes on a 5 mm circle. (BetaFPV product page)
• Shaft. 1.5 mm and unthreaded, standing 3.8 mm above the bell. (BetaFPV product page)
• Base. Four M2 holes on a 12 mm circle. (BetaFPV product page)
• Leads. Three 24 AWG wires: 80 mm on the 1550KV, 100 mm on the 2550KV by its drawing. (BetaFPV product page)

How fast it spins

KV is the motor’s no-load speed per volt. With nothing on the shaft, the 1550KV version reaches about these speeds; a prop loads the motor and brings it down, typically to around 70–75% of these figures at full throttle.

A 14-pole rotor has 7 pole pairs, so every turn of the shaft is 7 electrical cycles, and a six-step ESC switches the phases 42 times per turn.

About the 3D model

A generic outrunner drawn from BetaFPV’s published sizes: the 18 × 5 mm stator, 23.2 mm bell, 14.4 mm height, 1.5 mm shaft and 12 mm mounting circle. Anything BetaFPV doesn’t publish is typical for a motor this size, and the bell’s spoked top, the base and the inside are a generic design, not this motor’s. The colours are read off the maker’s product photos. There are no logos or markings: it is our drawing, not the maker’s.

Sources

1. BETAFPV: 1805 Brushless Motors (product page). Retrieved Oct 19, 2026.
2. BETAFPV: 1805 1550KV outline drawing and load performance table at 24 V (image on the product page). Rows step by thrust; BetaFPV leaves the throttle and coil temperature columns blank, so they are left out.. Retrieved Oct 19, 2026.
3. BETAFPV: 1805 2550KV outline drawing and load performance table at 16 V (image on the product page). Rows step by thrust; BetaFPV leaves the throttle and coil temperature columns blank, so they are left out.. Retrieved Oct 19, 2026.
4. BETAFPV: Comparison of 1805 Motors chart (image on the product page). Retrieved Oct 19, 2026.
5. BETAFPV: 1805 1550KV main product photo, used for finish. Retrieved Oct 19, 2026.