HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Aug 13, 2012, 08:34 PM
Registered User
Joined Aug 2012
3 Posts
Discussion
ESC, BEC values

The spec sheet for the ESC I am using lists the bec values as 5v/2a. Does this mean that the bec should shut down power delivered to the motor at 5 volts? My power source is a 3s, 2100 maH, Lipo, 25C. The esc shuts down motor power with battery voltage at just over 9 volts. Is this normal? Battery charges and balances OK.
texican is offline Find More Posts by texican
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 13, 2012, 08:40 PM
Registered User
dmcquinn's Avatar
Chesterfield (St.Louis) MO
Joined Jan 2004
320 Posts
The "5V/2A" means that while in operation, the BEC supplies a 5 volt power to the receiver up to 2 Amps of current. If the receiver and servos draw more than 2A of power, then the BEC is not suitable for this application. Two Amps is a lot of current - plenty for a sport plane under 5 pounds.

The ESC will quit supplying current to the motor at 9 V for a 3-cell LiPo. This is pretty typical as you don't want to discharge the LiPO to less than 3 V per cell.
dmcquinn is offline Find More Posts by dmcquinn
Reply With Quote
Old Aug 13, 2012, 09:57 PM
St. Louis
Foambird's Avatar
USA, MO, Ballwin
Joined Mar 2010
634 Posts
The BEC capability is fine for most airplanes unless you are pushing more that four servos with additional demands such as 3-D.

As a reference point, my P-47 with flaps and gear never drops the voltage below 4.9 no matter what you do. This is a stock ESC w/BEC. So if you fly "normal" aircraft "normally" you wont' need a separate pack.

I did this test aggresively and never saw an issue.
Foambird is offline Find More Posts by Foambird
Reply With Quote
Old Aug 14, 2012, 02:48 AM
Registered User
Staffs, UK
Joined Nov 2003
10,551 Posts
Bit of confusion there I think. The BEC is the part of the device that supplies power to the receiver and servos. It has nothing to do with shutting the motor down when the battery voltage gets low. That's a function of the ESC itself called LVC (Low Voltage Cutoff).

Steve
slipstick is online now Find More Posts by slipstick
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Dual ESC's w/BEC on a twin. rockom Power Systems 6 Jun 16, 2012 11:44 AM
Sold Value Hobby 60A brushless ESC NIP JimVanLoo Aircraft - Electric - Airplanes (FS/W) 0 Apr 29, 2012 04:59 PM
Sold 4 Hitec HS65HB servos, brushless motor, ESC and great value Hyperion VX G3 lipo crosby Aircraft - General - Radio Equipment (FS/W) 4 Mar 16, 2012 06:41 PM
Discussion Higher Amp ESC/BEC combo Vs lower Amp ESC + separate BEC DMala Micro Helis 2 Dec 09, 2010 03:20 PM
Discussion 2x esc-bec ? 2 Bec or not to Bec osprey Power Systems 4 Apr 20, 2009 02:33 PM