Choosing the right drone ESC can make a significant difference in performance and reliability. The electronic speed controller (ESC) plays a crucial role in adjusting the speed of motor based on data signals it receives from the throttle controller. In this article, we’ll delve into the key factors to consider how to choose a drone ESC, including compatibility, features, and performance to help you make the ultimate choice for your drone setup.
What is a Drone ESC？
A Drone ESC, or Electronic Speed Controller, is a vital component in an FPV drone system. It controls the speed of the motors by interpreting throttle signals from the flight controller. The ESC converts these signals into the precise three-phase current needed to drive brushless motors. This ensures smooth and responsive motor performance, crucial for stable and agile flight. Essentially, the ESC acts as a bridge between the flight controller and the motors, making it indispensable for optimal drone operation.
The Types of Drone ESC
There are two main types of drone ESCs: 4in1 ESC and single ESC.
4in1 ESC
A 4in1 ESC combines four individual drone ESCs on one board, each controlling a motor. This design simplifies the setup by reducing the need for extensive wiring and soldering, as the 4in1 ESC typically sits directly below the flight controller, connecting via a single wire harness. While the downside is that damage to one drone ESC means replacing the whole board, advancements have made modern 4in1 ESCs highly reliable. They also improve weight distribution, enhancing drone performance. Available in 30x30mm and 20x20mm sizes, 4in1 ESCs are ideal for different drone builds, with the larger size preferred for more powerful setups.
Single ESC
Single ESC, or Electronic Speed Controller for drone, manage one motor each on a drone. They used to be popular and are still a solid choice for newcomers. If a single ESC fails, you can replace it easily and affordably, which is beneficial if you’re likely to crash.
These drone ESCs are mounted on the drone’s arms, allowing better airflow and cooling. They connect to a power distribution board(PDB) or a flight controller with an integrated PDB, simplifying power connections.
However, using single ESCs requires more wiring and soldering, which can add weight and slightly impact responsiveness. For beginners, the lower replacement cost of a single drone ESC—about $15 versus $50 for a 4in1 ESC—makes them an economical option.
Drone ESC Recommendations
MEPS SZ60A 3S 6S 4in1 ESC-30.5×30.5mm
The MEPS SZ60A 4in1 ESC is a top pick for FPV pilots needing power and reliability. It handles 60A, making it great for freestyle and racing drones. Its design helps keep the ESC cool, ensuring stable flights.
For beginners, the SZ60A FPV ESC’s easy soldering is a plus, reducing setup issues. It uses BLHeli_32 firmware with bidirectional D-shot for quick response. With 30.5×30.5mm mounting holes, it fits most FPV frames. If you want a powerful, easy-to-use 4in1 ESC, the MEPS SZ60A is a strong choice.
SpeedyBee BLHeli_S 55A
The SpeedyBee BLHeli_S 55A 4in1 ESC is a great budget choice for FPV pilots. At just over $40, it’s affordable and reliable, offering up to 55A continuous current. I’ve used it for over a year, and it still performs well. Its 30.5 x 30.5mm size fits most frames, and it works with 3S to 6S LiPo batteries.
For even better value, you can pair it with the SpeedyBee F4 V4 flight controller, costing just under $70 for the stack. If you’re looking for a dependable and budget-friendly FPV ESC, the SpeedyBee 55A is a solid option.
Hobbywing XRotor Micro 60A
The Hobbywing XRotor Micro 60A is a top FPV ESC that offers great performance and features. This 4in1 ESC has a fast 32-bit processor, supports PWM, Oneshot, Multishot, and DShot1200 signals, and comes with either a plug-and-play connector or solder pads.
It includes large FETs for better efficiency, direct capacitor pins, and a 5V BEC to power accessories. A useful beacon function helps you locate your drone if it gets lost. Its compact 20×20 size makes it a reliable choice for any FPV setup.
Amp Rating
When selecting a drone ESC, understanding the amp rating is crucial. The amp rating, indicated as 15A, 30A, 40A, etc., shows how much current the ESC can handle.
Drone ESC has 2 ratings: continuous rating and the burst rating.
The continuous rating refers to the amount of current your drone ESC can manage over an extended period during regular flight. The burst rating, on the other hand, represents the maximum current the ESC can tolerate for short bursts, such as when you throttle up to 90-100%.
Choosing the correct amp rating for your drone ESC is vital because an underrated ESC may overheat and fail, especially during high-throttle maneuvers. The continuous rating ensures your ESC can sustain the current drawn by the motors throughout most of the flight, while the burst rating ensures it can handle sudden surges in power without damage. The continuous rating ensures your ESC can sustain the current drawn by the motors throughout most of the flight, while the burst rating ensures it can handle sudden surges in power without damage.
Mostly, three things can increase the current draw of your ESC,
- Higher KV values of the motor
- Larger propellers (length and pitch)
- Larger motor size (stator width and height)
Weight and Size
When selecting a drone ESC, weight and size are key factors to consider, as they are directly linked to the current rating. Most drone ESCs on the market today are fairly similar in size and weigh between 4-6g each. While lighter ESCs may seem advantageous, especially for racing drones, it’s important not to compromise on performance and cooling efficiency.
Smaller drone ESCs tend to heat up faster and may not cool effectively without sufficient airflow. Although some compact ESCs come with heat sinks, these are often inadequate for preventing overheating during intense flights. Therefore, when choosing a drone ESC, it’s crucial to balance the need for a lightweight setup with the necessity for reliable performance and effective cooling.
Below is the recommended drone ESC sizes to match:
| Propeller Size | Stator Diameter | Stator Height | Motor KV | ESC Size |
| 2″ | 11 | 03-06 | 4000-8000 | 6-12A |
| 3″ | 13-14 | 06-07 | 3000-4000 | 12-20A |
| 4″ | 13-22 | 04-07 | 2400-2900 | 20A |
| 5″ | 22-23 | 05-07 | 2200-2800 | 20-35A |
| 6″ | 22-23 | 06-08 | 2200-2800 | 30-40A |
| 7″ | 30+ | 06+ | 1800-2300 | 30A+ |
Lipo Input
You should be alright most of the time, but it’s a good idea to make sure your drone ESC can support the number of cells in your lipo. Up to four or six cell lipos can be supported by different ESCs.
Drone ESC Firmware
The ESC manufacturer’s firmware is the software that runs on each ESC. It determines the performance of the ESC. ESC device firmware provides information about configuration interface and supported protocols. There are different types of ESC firmware,
- BLHeli ESC.
- BLHeli_S ESC
- SimonK ESC
- KISS firmware
- BLHeli_32
Among these, BLheli firmware and Simonk firmware are open-source, and KISS firmware is closed-source, meaning it can only work with KISS ESC.
8. Drone ESC Protocols
When choosing a drone ESC, the protocol it uses is crucial because it affects how quickly the ESC and flight controller (FC) communicate. This communication speed impacts your quadcopter’s handling and performance.
Older protocols like PWM had delays of up to 2ms, while modern protocols such as Dshot and Multishot have reduced latency to just 5-25µs. Among these, Dshot600 remains a popular choice due to its balance of performance and availability. Although Dshot1200 offers slightly better performance, the difference is often imperceptible during flight. However, if you need to run a 32K/32K looptime setup, Dshot1200 might be necessary.
| Protocol | Latency |
| Standard PWM | 1000-2000 µs |
| Oneshot125 | 125-250 µs |
| Dshot150 | 106.7 µs |
| Oneshot42 | 84 µs |
| Dshot300 | 53.3 µs |
| Dshot600 | 26.7 µs |
| Multishot | 15-25 µs |
| Dshot1200 | 13 µs |
In summary, when selecting a drone ESC, consider the protocol’s latency and your specific needs. For most users, Dshot600 will provide excellent performance, but Dshot1200 is an option if you require higher looptime rates.
