SpeedyBee BLS 50A 4-in-1 (30x30)

The SpeedyBee BLS 50A 4-in-1 (30x30) is a 4-in-1 ESC from the Chinese maker SpeedyBee for FPV quadcopters in the 30 × 30 mm format. It runs BLHeli_S firmware and weighs 13.8 g. According to the manufacturer's page the model is discontinued.

The continuous current is 50 A and the peak current 55 A for 5 s, both per channel. The voltage window runs from 3S to 6S, i.e. up to 25.2 V fully charged. DShot300 and DShot600 are listed as signal paths; the number is the bit rate in kbit/s. There is no telemetry: the controller reports neither current nor temperature back to the flight controller. BLHeli_S is an older firmware generation for 8-bit processors that is no longer developed and has no Bidirectional DShot; anyone who wants to use RPM filters needs other firmware or another controller for that.

Frame and law: quadcopters with 50 A channels normally weigh more than 250 g and so lie outside class C0. From that take-off mass, operator registration and a proof of competence are due. On 6S an ampere-hour of battery is worth 22.2 Wh, and the IATA limit of 100 Wh lies at about 4.5 Ah.

Because the model is discontinued, the spare-part question belongs to the selection: a failure usually means replacement with another model, which the 30 × 30 mm format makes easier. On used units check the solder pads at the battery connection, the capacitors and the MOSFETs for burn marks; one failed channel affects the whole board.