Quick Reference
Motor KV Selection Guide
Symptoms / When to use this
motors overheatingshort flight timessluggish throttle responsehigh amp draw at hover
KV is the RPM-per-volt rating of a motor. Picking the wrong KV for your prop size and cell count wastes power, overheats motors, and kills efficiency. This guide maps KV to the most common FPV build sizes.
What KV Actually Means
KV is not a quality rating — it is how many RPM the motor spins per volt with no load. A 2400KV motor on a 4S (14.8V nominal) pack will try to spin at roughly 35,500 RPM unloaded. Add a prop and that number drops significantly under load.
KV vs Prop Size Rule of Thumb
- 3" props, 3S/4S: 2600–3000KV — high revs needed for small blade diameter.
- 5" props, 4S: 2300–2600KV — the most common cinematic FPV sweet spot.
- 5" props, 6S: 1700–1900KV — lower KV compensates for higher voltage.
- 7" props, 4S: 1700–2000KV — larger diameter needs fewer revs.
- 10" props, 6S: 900–1200KV — long-range / efficiency builds.
Stator Size
The stator dimension (e.g. 2306, 2207) tells you stator width × height in mm. Taller stators (e.g. 2308) produce more torque. Wider stators (e.g. 2507) run cooler under continuous load — better for cinematic builds that cruise rather than punch.
Signs You've Got the Wrong KV
- Motors hot after a 2-min hover with standard props = KV too high for cell count.
- Sluggish throttle response = KV too low, not enough RPM for the prop.
- Short flight times despite good battery = inefficient operating point, revisit KV/prop pairing.
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