BEC v/s wiring directly to 2s lipo

[big_poppa49]

Please I want someone to explain here rather than say "just use a BEC and you will see"

My and my son lost our stock servos in our SCX-10s. I ordered two Solar D772 high torque servos. People has been saying to run a external BEC (Castle 10A specific). Please explain the difference (if any) between running my servo powered directly to my 2s lipo and using a BEC?? I know the servo is rated for 4.8v, 6v, and 7.4v so I know the servo can handle the power.

Also, why such a high AMP BEC? Would a 3A/6v not work? Im a former/current r/c airplane guy and one one of my electric planes I use a Hobbywing 3A/5A max UBEC giving 6v to 5 sub micro servos in which all operate simultaneously at once. So I cant imagine needing a whopping 10A for a single servo.

Oh and I dont run in comps or anything, just crawl in different places local and creek beds and a spot I got fixed behind my house

Any input on this is appreciated. How do you guys have yours and what BEC do you use or do you just wire yours directly to battery?

I do understand if I ran 3s I would NEED a BEC but I dont plan to run 3s now, or probably not even in the future

 

[JohnRobHolmes]

Running 2s you don't need a regulator, but it can wear out servos faster because of the fresh charge voltage.

crawlers are a different beast than planes. where I might be able to run between 5 and 10 servos off of a castle bec, in a crawler just two servos can Brown it out under hard load. It is very telling that the average crawler (not basher or rock racer) spends a lot more battery on the servo than the drive motor. In other words, the majority of battery juice is spent steering a very slow moving rig. The last data logs I took showed just one servo taking more than twice the average amp draw of the drive motor.

 

[youngblood]

The last data logs I took showed just one servo taking more than twice the average amp draw of the drive motor.

This just blew my mind. :shock:

 

[big_poppa49]

Makes since from the fresh charge voltage

 

[JohnRobHolmes]

This just blew my mind. :shock:

Mine too. The first time I didn't have servo draw included, and somehow the motor used 800mah and my rig was dead. The remaining part of the 2200mah pack had to go somewhere right? I redid the wiring and low and behold the servo was taking more than the motor when crawling.

 

[JokersWild]

Mine too. The first time I didn't have servo draw included, and somehow the motor used 800mah and my rig was dead. The remaining part of the 2200mah pack had to go somewhere right? I redid the wiring and low and behold the servo was taking more than the motor when crawling.

I droped thr mah on my class 3 rig and have seen same thing with my servos sitting while rig is not in motion trying to center will chew through the battery pretty fast. Lol"thumbsup"

 

[big_poppa49]

Do you guys think it's fine to run this solar servo I ordered off the rx power for now until I can get a bec? I know it won't have as much power and torque but would it be fine?

 

[snapon boy]

I would wait till bec shows up . I killed 2 very nice escs doing that. However others have better luck than me and had no problems.