BEC stands for Battery Elimination Circuit. It’s just a fancy name for voltage regulator, which converts main LiPo battery pack voltage to a lower voltage (e.g. 2S 7.4V, 3S 11.1V or 4S 14.8V to 5V). BEC is usually built into ESC, and as the name suggests, it eliminates the need for a separate battery to power the 5V electronic devices.

UBEC stands for universal BEC or sometimes ultimate BEC. It’s used when ESC doesn’t have built-in BEC, or standalone power system is required. They generally are more efficient, more reliable and able to provide more current than BEC. The UBEC is connected directly to the main battery of the multicopter, the same way as an ESC.

Why Use UBEC over ESC BEC?

In layman’s terms, UBEC has the following advantages over ESC built-in BEC:

• UBEC are more power efficient
• BEC tends to overheat with large input/output voltage difference, or large load; UBEC doesn’t have this problem and thus more reliable
• UBEC generally can provide more current safely

The reason behind these are due to the way how voltage is regulated. Most BEC are linear type, and UBEC are switching type. For a more technical insight, please carry on to the next section: Linear BEC VS Switching BEC.

If your ESC don’t have BEC, you can use an external UBEC to power your FC and RX. The UBEC’s input cable should be connected to the LiPo battery, and the output cable to the RX and FC. No change is required in the ESC connection.

But if you want to power your FC and RX with an UBEC, while your ESCs have built-in BECs, those BECs first needs to be disabled/disconnected from your system. Simply remove the red wire (5V) from the output servo lead of the ESC.

And what is Cooling Fan?

A cooling fan is made to flow cooler air over electric speed controller, to protect electric speed controller overheat and extend controller's life span. 

Currently most cooling fan in the market only has 5W-10W power, our cooling fan is 20W power, can faster and more efficiently cool your speed controller. 

Below video check the 20W cooling fan constantly working over 30min and still working in normal temperature: