When to use a Castle Creations BEC

Tony Phalen September 11, 2017 RCD Electric

What is a BEC? That’s a question I’ve heard quite a few times over the years. Before the BEC (we’ll get to what it is in a second), drivers used to install small, four-cell battery packs on their cars to power the electronics. Why? Well, back in the day, we’d need to use as much of the power in the NiCd and NiMh battery packs as possible to run the cars in a simple four-minute race. We couldn’t afford to use any of the power in that six-cell pack to power the servo or receiver so an additional ‘mini’ pack would be installed onboard our rides. Yah, I know, it sounds odd since today’s LiPo/brushless setups can be run for 30-minutes or more while powering the electronics, lights, winches or even onboard Bluetooth radios, but that’s the way it was.

In turn, with better batteries come bigger brushless setups, and that enormous power draw can cause issues while trying to feed juice to the other components on the car. Enter the BEC, which stands for Battery Eliminator Circuit. How it works is quite simple; when you pull full throttle on your high-powered rig, a huge spike in energy travels from the battery to the motor (through the ESC). This spike can be so big that power to the servo and receiver can be reduced, thus causing a slight stutter or even a momentary loss of control.

So the BEC is, essentially, a storage container for additional electricity. It converts the input voltage down to 5V for use in your servos and receiver. Internal BEC’s are typically linear, meaning they do their conversion and expel the remaining voltage as heat. This can cause things to get hot fast, especially if you’re running a 3S (11.1) or higher battery setup.

The solution? Install one of Castle Creation’s external BECs. This is a switching-type system which reduces voltage by switching on and off very quickly, creating a lot less heat. This setup is perfect for applications that use multiple servos or rigs that operate on more than 3S LiPo, like crawlers or larger monster trucks. Installation may vary slightly depending on your setup and might require you to do some solder- ing. Make sure, though, that if you choose to go with a Castle BEC that you disable your ESC’s built-in BEC (if it has one).

TOOLS NEEDED TO INSTALL A BEC
-Soldering Iron
-Solder
-Wire Strippers
-Shrink Tubing

INSTALLATION
Need help installing a Castle Creations BEC? We’re here to help. We’ve created a video that helps walk you through the process of soldering a BEC into your vehicle. With a little bit of time and some general hobby tools, you’ll have the power your servo needs in no time.