Skystars AM32 KM55A 55A 3–6S 20×20 4-in-1 ESC

The Skystars KM55A is a high-density 4-in-1 ESC that packs 55A of continuous current per channel into a compact 20x20mm mounting footprint. Running on the open-source AM32 firmware, this ESC is built to handle the aggressive current spikes of 5-inch freestyle and racing drones, while remaining lightweight enough to power demanding 3.5-inch and 4-inch builds.

Key features

• Pre-flashed with AM32 32-bit firmware for smooth low-end motor control and highly configurable variable PWM frequencies.
• Delivers a massive 55A continuous current rating per channel on a space-saving 20x20mm board.
• Fully supports bidirectional DShot out of the box, enabling advanced RPM filtering in Betaflight.
• Broad 3-6S LiPo input compatibility handles everything from sub-250g rippers to full-size 6S heavy-lift freestyle quads.

Specifications

• Continuous Current: 55A (per channel)
• Input Voltage: 3-6S LiPo
• Firmware: AM32
• Protocol Support: DShot300, DShot600, Bidirectional DShot
• Mounting Size: 20x20mm

Because AM32 serves as an open-source alternative to BLHeli_32, you can easily flash, configure, and tune motor timing or startup power directly via the web-based AM32 ESC Configurator using your flight controller's USB passthrough.