iFlight BLITZ E55S 4-in-1 ESC

The iFlight BLITZ E55S 4-in-1 ESC is a 4-in-1 controller from the Chinese FPV maker iFlight for 5-inch quadcopters. Four controllers and a current sensor sit on a board of 30.5 × 30.5 mm; it weighs 14.7 g, the Mini variant of 20 × 20 mm 11.3 g.

The continuous current of 55 A and the peak current of 65 A apply per channel. For the peak current the manufacturer gives no duration, so the 65 A serves only as a short buffer, not as an operating point. The voltage window runs from 2S to 6S, i.e. up to 25.2 V fully charged. The signal paths listed are DShot150, 300 and 600, MultiShot and OneShot. The firmware is BLHeli_S or Bluejay: both run on 8-bit processors, which fits the limit at DShot600. BLHeli_S has no Bidirectional DShot, whereas Bluejay brings the speed feedback for RPM filters.

Frame and law: a 5-inch quadcopter is normally above 250 g, so outside class C0. From 250 g take-off mass, operator registration and a proof of competence are required; that concerns the operator, not the ESC. On 6S an ampere-hour of battery is worth 22.2 Wh.

For selection the firmware decides: anyone who wants to use RPM filters needs Bidirectional DShot, i.e. Bluejay or a controller with 32-bit firmware. Typical wear in FPV flying is torn-off solder pads at the battery connection, crushed motor leads and MOSFETs strained by prop strikes; the failure of one channel affects the whole board.