BEC FAQ

[cbr6fs]

Hi Peeps,

Just Read through this and I'm having a "Beaker moment", It apears I was wrongly advised that bec's are only for nitro's,

I'm Using flux motiv esc (7.2v) and standard HPI firestorm servo (6v) and Ansmann Racing 3.1 RX.

Is it still advisable to use a bec with this setup or wait till I have to replace the servo with somthing better?

Cheers

Jason

Bit late sorry Jason but i have only just seen you post.

Really depends on what your after.

If you are not experiencing any problems like glitching or brown outs then i'd wait till you get a better servo.

In my experience there is a gain to be had on pretty much any car and system by using a decent BEC, if a cars steering is not being pushed to the limits though that gain may well not be noticable for the majority of driving.

I run a 6s lipo on my brushless losi 8ight T though i use a hobbyking esc. How do I program it if it isnt an MMM esc?

Jay

Absolutely no idea, last time i looked hobbyking were selling a lot of BEC's so yours ould be one of many.

Your best bet is to contact hobbyking or look on your BEC's order page and see if there is a PDF manual listed.

If not then a quick google search should bring up the answer.

Cheers

Mark

[suicideneil]

^Don't confuse a BEC with an ESC; the BEC is built into the ESC

There is nothing to actually gain from using an external or separate BEC, if your servo(s) is working fine being powered from the ESC's internal BEC- only if you are experiencing power loss or loss of control ( caused by the servo drawing too much current ), or the ESC is running hotter than you expect it to is it worth running an external BEC to power the servos. Ofcourse, if you want the full 6v ( instead of more like ~5.5v ), or you want to run a HV servo ( which needs 7.2v or more ), then it's definitely an idea to run an external BEC capable of out-putting that much voltage & enough current to cope with the servo's needs.

[cbr6fs]

^Don't confuse a BEC with an ESC; the BEC is built into the ESC

There is nothing to actually gain from using an external or separate BEC, if your servo(s) is working fine being powered from the ESC's internal BEC- only if you are experiencing power loss or loss of control ( caused by the servo drawing too much current ), or the ESC is running hotter than you expect it to is it worth running an external BEC to power the servos. Ofcourse, if you want the full 6v ( instead of more like ~5.5v ), or you want to run a HV servo ( which needs 7.2v or more ), then it's definitely an idea to run an external BEC capable of out-putting that much voltage & enough current to cope with the servo's needs.

Problem is Neil there is no "one solution fits all" it really depends on the ESC, car, driving environment, servo, driver, steering components and many many other things.

So your statement is really to vague to be useful.

As an example on CC Esc's their internal BEC's are pretty terrible, but their servo's they fit on their RTR's are even worse so there is very little noticeable gain by fitting a separate BEC.

Fit a decent aftermarket servo though and the Esc's BEC really starts to struggle very quickly.

Many don't notice though as it's still a million times better than the stock servo they had before.

On a touring car for example the extra torque really isn't needed, BUT don't forget if you have a clean consistent power supply to your servo your steering will be more consistent.

Likewise if you bump up the voltage slightly you will have a slightly faster servo.

On crawlers i've yet to see a crawler that didn't experience a MASSIVE gain by fitting a BEC.

Likewise on bigger wheel'd off-road cars like say the ERevo, Savage etc.

Even my Blitz was noticeably better with an external BEC fitted

So it's my opinion that if you have the funds, can put up with the extra wiring and have space available it's a no brainer, fit a BEC.

On my touring cars/drifters i have found a small gain from fitting a BEC, but that small gain is outweighed by having all that extra wiring everywhere IMO, so in this instance i don't bother fitting a external BEC even though there is a small noticeable improvement.

As most of us have a 4 x AA battery holder knocking around in our tool boxes (as used in many Nitro cars) if your unsure then the best bet is to spend 10 mins slapping together a harness, then just try the car running the servo from the 4 x fully charged AA cells.

If you notice a gain, have the funds and space and don't mind about the extra wiring then jobs a god un

Cheers

Mark

[suicideneil]

Problem is Neil there is no "one solution fits all" it really depends on the ESC, car, driving environment, servo, driver, steering components and many many other things.

So your statement is really to vague to be useful.

My statement was clear and precise about when an external BEC is appropriate or not ( worth bothering with )- I didn't offer a 'one solution fits all' piece of advice as it happens.

As an example on CC Esc's their internal BEC's are pretty terrible, but their servo's they fit on their RTR's are even worse so there is very little noticeable gain by fitting a separate BEC.

Which is exactly what I said.

Fit a decent aftermarket servo though and the Esc's BEC really starts to struggle very quickly.

The BEC won't 'struggle' in the way you are implying- the steering will either work fine, or the ESC will start cutting out when you work the steering too much or too hard ( which is what I see guys complaining about usually ). The ESC may also run hotter than you expect it to but will still run fine with no loss of control; which is also exactly what I said. Digital servos won't just put out half power if the BEC is struggling- they'll work fine/better based on the voltage they get- if the current supply isn't strong enough then the voltage will drop > no control as the ESC cuts out. Upto that point it'll work fine- never seen anyone complaining about their steering lacking power suddenly, have seen them say the throttle & steering dies until they release both to neutral.

Many don't notice though as it's still a million times better than the stock servo they had before.

See above.

On a touring car for example the extra torque really isn't needed, BUT don't forget if you have a clean consistent power supply to your servo your steering will be more consistent.

Likewise if you bump up the voltage slightly you will have a slightly faster servo.

On crawlers i've yet to see a crawler that didn't experience a MASSIVE gain by fitting a BEC.

Likewise on bigger wheel'd off-road cars like say the ERevo, Savage etc.

Even my Blitz was noticeably better with an external BEC fitted

If your steering response is that poor when running the internal BEC then fair enough, but a servo powerful to tax the BEC would be fairly evident so hence the external one providing better power. You'd know if it was the stock servo being weak, or the new servo overloading the internal BEC though ( well, if you posses problem solving abilities and some fairly basic electrical knowledge- some guys are totally clueless so getting upto speed on the basics is a struggle, let alone something more advanced like ohm's law & such ).

So it's my opinion that if you have the funds, can put up with the extra wiring and have space available it's a no brainer, fit a BEC.

On my touring cars/drifters i have found a small gain from fitting a BEC, but that small gain is outweighed by having all that extra wiring everywhere IMO, so in this instance i don't bother fitting a external BEC even though there is a small noticeable improvement.

As most of us have a 4 x AA battery holder knocking around in our tool boxes (as used in many Nitro cars) if your unsure then the best bet is to spend 10 mins slapping together a harness, then just try the car running the servo from the 4 x fully charged AA cells.

If you notice a gain, have the funds and space and don't mind about the extra wiring then jobs a god un

Cheers

Mark

Remember what I said about the internal BEC's output voltage- you're bound to notice a difference between ~5.5v & 6v as that represents a ~9% increase. Some only output 5.1v, and that's without a load on it; a good friend tested the output voltage of some BECs with an increasing load once and found that it cut out right around the ~4.5v region I believe it was, but by then he was drawing it's rated current too which you would rarely do for a prolonged period. However, given the price of digital servos though you'd notice a night and day difference between a stock ~150in/oz .25sec/60

[J450n]

Okies, thanx for clearing it up

Cheers

Jason

[The Dark Knight]

I'm wanting to fit a Castle BEC to my Savage XS SS,  it has a Hobbywing SC8-WP 120a esc, a Castle 3800kv motor, a Savox 1256 servo and I only run 2S lipos. I run the truck pretty much everywhere and anywhere.

 

Will I better to connect up the BEC with option #1 or #2 as shown is this thread?

[RC Freaks]

Never seen the point in a BEC to be honest, this is all solved with a power cap in the receiver. Cheaper. Easier. Does the same thing.

 

I put a 30kg digital savox in a Mamba max and sure, it cut the ESC under quick steering. Add a power capacitor to the aux or bind port of your receiver and hey presto ... no voltage drop ...

[The Dark Knight]

Thank for your advice but from what other people have said, I will be better off with a BEC.

 

So my question still stands, will I better to connect up the BEC with option #1 or #2 as shown is this thread?

[Jacksprogis]

Thank for your advice but from what other people have said, I will be better off with a BEC.

 

So my question still stands, will I better to connect up the BEC with option #1 or #2 as shown is this thread?

You DO need a bec mate

I connect mine on Option 1 

Never had a problem , Never run a car without one .

Jack.

[The Dark Knight]

You DO need a bec mate

I connect mine on Option 1 

Never had a problem , Never run a car without one .

Jack.

 

Thanks Jack. Is the Castle 10A BEC suitable or is there something better for the money?

[Jacksprogis]

Thanks Jack. Is the Castle 10A BEC suitable or is there something better for the money?

Castle ones are the best .

You could get a hobbyking one but the 10a ones are only

[.AJ.]

I used to run a Savox 1258 on crappy

[The Dark Knight]

I used to run a Savox 1258 on crappy

Edited April 16, 2013 by The Dark Knight

[.AJ.]

I don't with the Xerun 120 and a 1258

[cbr6fs]

I'm wanting to fit a Castle BEC to my Savage XS SS,  it has a Hobbywing SC8-WP 120a esc, a Castle 3800kv motor, a Savox 1256 servo and I only run 2S lipos. I run the truck pretty much everywhere and anywhere.

 

Will I better to connect up the BEC with option #1 or #2 as shown is this thread?

 

No real best, it all depends on what you want to do.

 

I run option #2 as i don't want my Rx blacking out if i bind, but either will work fine.

 

 

 

Never seen the point in a BEC to be honest, this is all solved with a power cap in the receiver. Cheaper. Easier. Does the same thing.

 

I put a 30kg digital savox in a Mamba max and sure, it cut the ESC under quick steering. Add a power capacitor to the aux or bind port of your receiver and hey presto ... no voltage drop ...

 

Completely different thing.

 

A capacitor is usually used to prevent or cure glitching, it's a poor choice for powering a servo though.

 

Hobbyking have a few to choose from, they call them UBEC's though?

 

Do you run a BEC on your buggy too AJ?

 

BEC stands for Battery Elimination Circuit

UBEC stands for Universal Battery Elimination Circuit

 

There is no difference in function between the 2 it really just comes down to which brand you prefer

[RC Freaks]

Completely different thing.

 

A capacitor is usually used to prevent or cure glitching, it's a poor choice for powering a servo though.

Fair enough, Didn't realise that's what the BEC was for. You're not the first person to correct me today, albeit not sarcastically.

[The Dark Knight]

I don't with the Xerun 120 and a 1258

 

Ok cool, thanks AJ, I'm just planning ahead for when I get my buggy  I'll fit one to the Savage XS SS though.

 

 

No real best, it all depends on what you want to do.

 

I run option #2 as i don't want my Rx blacking out if i bind, but either will work fine.

 

 

 

 

Completely different thing.

 

A capacitor is usually used to prevent or cure glitching, it's a poor choice for powering a servo though.

 

 

BEC stands for Battery Elimination Circuit

UBEC stands for Universal Battery Elimination Circuit

 

There is no difference in function between the 2 it really just comes down to which brand you prefer

 

Thank you for the info, it's much appreciated, I'll go for option #2

[Phil-RC]

I hava a Mamba XL2, CC Bec and a CC Cap pack. Using EC5 connectors.

 

Where is the best location to connect the bec?

 

A ) Battery connectors.

B ) ESC battery wire solder points.

C ) CC Cap pack posts.

 

           Cheers

 

               Phil

Edited February 24, 2014 by Phil-RC

[Phil-RC]

Update:-

 

I went ahead and soldered the CC BEC to the bottom of the cap pack posts. Note:- You cannot use the Castle link directly from the usb to program the BEC if its connected to the esc without a switch as the esc and BEC draw too much power. You have to connect up the your battery pack(s) to the esc to get it to recognise the BEC. Its explained in the castle link software help with connections.

 

          Cheers

 

              Phil

[RCTROJAN]

Hello I am working on a project which involves me using 2 high torque servos on a basic touring car , my rx is the Spektrum sr300 , the vehicle works well with the 2 servos for 10 mins then utter fail and brown out rx led fades out , bought the Spektrum spm1600 cap for the rx and the vehicle lasted 30 mins without brown out , ,, so now I'm assuming I need a bec to feed current to the rx ? I've been looking for bec 's and I'm very confused on what one to buy as I'm running 2 servos and a light kit Do I get the cc bec 10 amp ?or do I get the Cc pro bec 20 amp ? Or do I scrap the sr300 rx and get a superior rx ? Cheers guys

Edited April 14, 2014 by RCTROJAN

[Krimz88]

Hi,

 

I am about to upgrade my Vorza to have the following:

 

- spektrum srs4210 avc receiver

- Savox 1258 Servo

- Castle BEC

 

 I know to run the above I need to install a dedicated BEC. My issue is that I can not for the life of me seem to work out how to gain access to the ESC to splice/solderdirectly to the battery terminals on the

esc? 

 

I found the image below in a post, but could not see how they gained access or had enough space to solder.

 

Advice would be much appreciated 

[Hardcore]

Just about to install a BEC myself and had a few questions...

Has anyone used either the Turnigy "5amp" BEC or the Hobbywing 3amp one?
The Turnigy one is huge in comparison and has a capacitor and the Hobbywing doesn't.

Although the Turnigy is marketed as 5amp, that's peak and it's really 3amp as well. I was wondering if the added size and the fact it has a capacitor is any indication it's going to be better in some way.

Also, can i put my BEC beside my FM receiver without any issues?
Should i keep the ferrite ring on it ?

[ElectronShifter]

Servo failed on my sons Outback Fury after only 10 hours of trails.  Got an amazon special (as it’s very difficult to get spares locally atm) and put on a hobbywing UBEC at the same time.  I like the idea of the extra redundancy and load separation.   

I am going to do the same for my FTX Carnage to ensure I can steer rather than have brown-outs if the battery is getting low (NIMH). 

[ElectronShifter]

On 03/02/2017 at 21:37, Hardcore said:

Just about to install a BEC myself and had a few questions...

Has anyone used either the Turnigy "5amp" BEC or the Hobbywing 3amp one?
The Turnigy one is huge in comparison and has a capacitor and the Hobbywing doesn't.

Although the Turnigy is marketed as 5amp, that's peak and it's really 3amp as well. I was wondering if the added size and the fact it has a capacitor is any indication it's going to be better in some way.

Also, can i put my BEC beside my FM receiver without any issues?
Should i keep the ferrite ring on it ?

Howdie Hardcore,

My son has only had 2 runs with the UBEC Hobbywing (3A). No issues.  The instructions did recommend keeping the UBEC 25mm away from the RX to avoid interference.  I think this is because the switching noise must be quite high given the circuit isn’t heavily shielded.  I hot glued the ferrite ring to the inside of the RX box to keep it from clanging around, definitely keep this as it is reducing interference going back to the RX via the cable.