How to Choose an FPV ESC: Current, Voltage and Protocols
The ESC, or electronic speed controller, takes the flight controller's commands and drives each motor. A wrong choice is a common reason for burnt boards, so it pays to size it properly.
Current rating
Choose by the continuous current rating, not the burst figure. Read your motor's maximum current on your propeller, and pick an ESC whose continuous rating sits comfortably above it. Headroom keeps the ESC cool and gives you a margin for a bigger propeller later.
Voltage and cell count
Every ESC lists the cell counts it supports, for example 3S to 6S. Never connect a battery with more cells than the ESC is rated for. Long-range and heavy-lift builds often run on higher voltage, so check the rating before you pick the battery.
4-in-1 or single ESCs
A 4-in-1 ESC puts all four motor drivers on one board, which keeps a small build tidy and light, and pairs with a flight controller in a stack. Four single ESCs, mounted on the arms, spread the heat and are the norm on large frames, and one failure does not take the other three with it.
Mounting pattern
Small and mid-size builds use a 20x20 or 30.5x30.5 mm mounting pattern, with M2 or M3 screws respectively. The ESC and the flight controller must share a pattern for a stack, and it must fit your frame.
Firmware and motor protocol
Common ESC firmwares include BLHeli_S, BLHeli_32, AM32 and Bluejay. The flight controller talks to the ESC over a digital protocol, most commonly DShot, at a speed such as DShot300 or DShot600. Check that your flight controller and ESC support the same one.
Protect the electronics
Solder a low-ESR capacitor across the ESC's battery pads. It absorbs the voltage spikes that motors create, and protects the ESC and the rest of the electronics. Match its voltage rating to your battery.
