RCU Forums - Help on BEC

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- Esky Helicopters (https://www.rcuniverse.com/forum/esky-helicopters-481/)

- - Help on BEC (https://www.rcuniverse.com/forum/esky-helicopters-481/7701042-help-bec.html)

I wanto buy the following ESC and BEC but I don't know is it compatible with each other. Can someone see it and let me know? I'm installing both of it on my Stock Belt-CP. I don't have a ferrite ring. I use 3S1P 11.1 2200mah 20c Lipo, Tower Pro sg90 servo. Which BEC you recommend for the ESC?

ESC
GWS Brushless ESC 35A 2-4S 3A BEC, Speed Controller.
Weight: 22g
BEC: 3A

BEC1
Spec.
Output: 5v/3A or 6v/3A (Selectable via jumper)
Noise: <50mVp-p(@2A/12v)
Input: 5.5v-23v (2-5S Lipo pack, 5-15cells NiMh)
Size: 41.6x16.6x7.0mm
Weight: 7.5g

Features:
Over current and over heat protection.
Switching frequency 300khz.
Chip Efficiency is 92%. This UBEC utilises switching technology to gain a much higher efficiency than liniar BEC. Which means less heat and longer battery life.
The UBEC is equiped with a noise reduction alloy housing to reduce noise even further.
Incorrect polarity safety feature ensures the UBEC will not be destroyed should the battery be connected incorrectly.
https://www.unitedhobbies.com/UNITED...idProduct=4319

or BEC2
Spec.
Output (Constant): 5v/5A or 6v/5A
Input: 8v-42v (3-10cell lipo) High Voltage
Size: 48x27x9mm
Weight: 37g
Quiescent current: 20mA

Features:
Type: Switching, however because of the noise reduction (thin metal case & filter) this unit gives the same noise as a Linear BEC.
https://www.unitedhobbies.com/UNITED...idProduct=6320

I tried to check and get security warnings on that site.

I edited and posted up the specs in case you can't go to the website =) I need to buy it soon, all comments will be appreciated.

The esc you have there has a bec built in doesn't it? Or are you going to run a separate Rx batt.??

The ESC have a built in Linear BEC. What is a seperate Rx? Forgive me, I'm noob in this ESC and BEC thing

You don't really need 5amps for a 450 size heli but depends on the price.

You can use any BEC w/ any ESC, you have to match the ESC to the motor and battery. You have to match the BEC to the current draw of the electronics and the # cells in the battery. Remember to remove the red wire from the esc to the receiver when using a ubec.

If you buy a ESC with the BEC built in you don't need to buy a separate BEC. You buy a separate BEC when you like fly large helis and planes and you want to have a separate battery for the RX so if you fly out all your motor battery you still have battery for the Rx(Receiver) and can land your heli or plane. There are other reasons also. But for a BeltCP or a Honey Bee King 2 I think a built in BEC will work fine for you. But you should have a 30 to 35 amp esc for the Belt cp just because there have been some problems running smaller ones and them catching fire.

I have a Dynam 30amp esc that gets very hot with just 1 Lipo, for no reason it just reduce my heli throttle speed and cause my heli to drop down in the middle of the air. So I though I'll just get this 35amp ESC and a UBEC (since is only$20 to help reduce heat) to avoid any future unwarned speed reduce or fried my lousy Esky Digital servo. So, the above ESC are compatible with either BEC1 or BEC2 and can be fix into my stock belt-cp brushless motor?

You need to solder the ubec in parallel with the esc to the battery connector, then remove the red wire from the esc to receiver.

the linear becs in most escs are not great, especially if you're using a spektrum receiver.

Thank you everyone, found the Finless Bob video on how to piece ESC and Bec together

That seems to be a problem with the Dynam ESC it cuts off the the motor if it overheats OR the battery is low. On mine there Idea of a slow down is more like turn the switch off!
First and last Dynam I will run. Back to a RC Exceed next time as they have more programing features.
If the motor is turned off on the ESC you still have power to the servos to control the landing...somewhat.
Bec on most of these small ESC are at about 5.1 volt and can handel 5 servos (king has 4 and a gyro that counts as one also so a total of 5)

Dimension Engineering has the best BECs for the money. I run a 6 Volt one and Dynam 30 AMP ESC with no issues on stock servos and Hitec HS-81 for my tail. It was donated, otherwise I would have chosen the 5 volt version. My Dynam 30 Amp, came programed for Hard timing(Double Beep on start up) This will lessen run times and run hotter but have tons of power. I don't have much faith in the cut-off for the Dynam because mine will consinstantly run the Helo below 3 Volts per Cell ( I run an onboard monitor) Consenquently, I think I have been running my LiPos too low for about 6 months now and will need new ones soon. The onboard monitor is the ticket to avoid this. United Hobbies has one for a few dollars. I think I spent $9 for a voltmeter and onboard monitor shipped. Well worth it in my book.

I noticed that also that the Dynam ESC runs my battries down too far also. Have to watch the power drop off a little more closely/ I dont have any problem with heat with the hard timing set at I believe its the 2nd postion, I run a 3900 motor and 15c batteries, NOTHING even gets more warm (actually the motor is cool to the touch. Might have a tight pinion or belt too tight if your motor is getting hot. Batteries get only warm same with the esc.

your battery checker look like this? I have a box of of these I am going to sell off someday. Notice that they are only accurate to .1 volt even though they read to .01. Just round it up or down.