RC Basics: Is An External BEC What You Need?
There are many stories about external BECs due to the simple fact as most ESC's have a built-in BEC. However, did you know that most internal BECs only have an output voltage of 5 Volts at 2A?
The 5 volt supplied by the built-in BEC will have to power your servo and accessories, such as lights and winches. Now it just may be that you never had any issues and that’s perfectly fine! However, considering the fact that most servos nowadays can easily handle 6 volt, with the 5 volt you are infact underpowering your servo by an average of 20%!
So those people, for example, claiming their Savox SW0231MG will provide 15 KG (208 Oz-in) of torque, will actually “only” give you an average of 13 KG (180 Oz-in).
Crawler guys love strong servos. The Savox SB-2273SG which has a torque of 23 KG (319 Oz-in) at 6 volts, is a very power hungry servo, but will give you good torque. You may even encounter the phenomenon that while steering, your car may slow down. When that happens, your servo is draining too much power, which results in less power going to your motor.
Ever had a very hot ESC? This also might be your internal BEC's fault. There's too much power being consumed, which leads to a very hot ESC. An external BEC will solve your problem. If you don’t have a problem, it will make sure your servo and other accessories get the voltage they deserve and make them work at the most optimal level. Your motor will get its full power from the ESC itself, while all other accessories get their power through the BEC.
An external BEC like the ZTW/300100010 uses a jumper to make you choose between 5 volts and 6 volts. All you need to do is solder on the power leads to the plug that leads from your battery to your ESC. It's as easy as that. Then, from the cable that leads from your ESC to the receiver, you remove the red wire by lifting the little notch and pulling the red wire out. Plug the other end of your BEC into the third channel of your receiver and watch the magic!
Your servo will be faster and stronger. Your lights (which can easily handle up to 7 volts) will burn brighter. Your winch will be a bit faster and stronger! Don’t worry about your receiver. Most modern receivers can easily handle up to 9 volts!
Now, just another thing. These days there also are many servo’s that can handle 7.4 volts (HV= high Voltage Servo’s).
For those HV applications, there are even stronger BEC’s available like the ZTW/300300010. A very luxurious BEC that provides a lot of voltage options and can handle 12 Amps.
Watch the video below for a “how to”!