Running 2s with internal bec set at 8v
 

I'm running a Mamba x with a the bec set at 8v and was wondering if it was ok to leave it at that setting while using a 2s battery. The setting is to feed a HV servo. I know a 2s is 8.4 fully charged but when it drops is what I was worried about. Will it start to glitch?https://uploads.tapatalk-cdn.com/201...a719330008.jpg

Re: Running 2s with internal bec set at 8v
 

Sorry I don't know the answer, but your question raises a question for me. I was told with the Mamba X I don't need an external BEC. I have one in my SCX10 II and my Bomber and haven't seen any brownout issues. But should I be running a BEC?


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Running 2s with internal bec set at 8v
 

Depends on what the servo is asking for , under load. I would either run 3s or set voltage at 7.4 tops
A BEC regulates voltage, you need a transformer to raise voltage ...


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Re: Running 2s with internal bec set at 8v
 

I see, so with the internal bec's brain trying to push 8v without that much voltage supplied to the esc there will be problems?

This was a discussion a while back about not having the option to change the voltage in .5 increments let alone .1 on the MX's int. bec.
I guess I'll just set it at the next lower setting which is 7v.
Only reason why I like to use a 2 cell is because in real technical stuff, it has smoother control. I might try and find a better solution while using 3s and expo/throttle curves to achieve the right start up smoothness I need.

Re: Running 2s with internal bec set at 8v
 

I'd forgotten about the .5 increments. I'm running both a ProModeler470 and a Holmes HV500 both at 8.4v. I'm swapping a broken MMP (socket failed) for the new X , my thought was I don't want my rx at 8v so I'm at a disadvantage without my external bec....


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Re: Running 2s with internal bec set at 8v
 

Having an ext. bec is really the best way to go... when your rx is constantly at 8v you can't feed in lighting, lower voltage winches etc. The new Castle 2.0 is watertight and has good reviews.

Re: Running 2s with internal bec set at 8v
 

If the battery voltage is lower than what the BEC is set to, it goes wide open.

Re: Running 2s with internal bec set at 8v
 

You shouldn't need one unless you want to run different components at different voltages.

Re: Running 2s with internal bec set at 8v
 

The internal BEC will try to regulate the voltage to be as close as it can to the desired voltage. If the set point is too high, the BEC will keep the voltage half a volt under the input voltage.

Re: Running 2s with internal bec set at 8v
 

Close. A transformer can raise or lower voltages, but only on AC systems.

On DC systems a BEC is typically a 'buck' voltage regulator which lowers the voltage, but they make 'boost' voltage regulators that can raise the voltage. They make some of these for 1s racing.

Re: Running 2s with internal bec set at 8v
 

So basically linear regulators that "chop" the input voltage and burn the rest as heat? I thought that switching regulators were the norm, at least in higher end ESCs. More efficient and can raise voltage.

Re: Running 2s with internal bec set at 8v
 

--- skool me ---

what RX reliably holds up to 8 volts run thru ?

surface or air TX/RX ?

I have a "surface" RX that claims to handle up to 7.4 volt...
But I wouldn't think it wise to push my luck and test its reliability much above that.

I generally supply my RX with 6v from the ESC's internal BEC.
But I'd think 8v + could cause premature failure and I'm not so sure there would be any real world improvement !?

I don't power accessories off my RX.
Neither my winch/WWC nor 700 oz in servo draws thru the RX. (RX by-pass)
So I'm not sure why I'd even want to push 8v thru my RX ?

Some have claimed to run 8v thru this particular surface RX...
So maybe it'll hold up for a bit... but would it remain stable/reliable at 8v + ?

I've read of RC aircraft folk pushing to 8v with their 8 ch "air" TX/RX
But haven't read much about "surface" TX/RX utilizing 8v +

I wouldn't assume that it actually improves communication speed /or distance of a surface TX/RX...
and is still considered legal for surface use ?

So maybe it applies to a specific TX/RX ?

Not sure I'd need more RX voltage anyway... but skool my curiosity.

Thanks

Re: Running 2s with internal bec set at 8v
 

A lot of Spektrum rx's can handle up to 9.6v. For this application it's an SR410.
This is a surface rx. Some of the airplane rx's that are 8 and 9 channel that are in my Uncles choppers are capable of the same with one I believe being ran 3s voltage if desired, I think it was an Aurora by Hitec but not 100%

Re: Running 2s with internal bec set at 8v
 

Wish this came up in the searches I did for BEC and Mamba X.

So I don't need my external CC BEC with the Mamba X? I'm running a wraith with a sensored 3800kv crawler from castle with a hightec HS-7955TG.

Re: Running 2s with internal bec set at 8v
 

No need for wiring in your bec. [emoji106]

Re: Running 2s with internal bec set at 8v
 

I'm going to run one as my servos run at 8.4v and not my RX


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Re: Running 2s with internal bec set at 8v
 

Good point Mike made. No need to wire in your bec with the X, unless of course your RX can not handle high volatage.

Re: Running 2s with internal bec set at 8v
 

Back to one of your earlier suggestions, I run almost all of my rigs now on 3S (including two kit 10.2s), usually geared down from stock and always with expo throttle control. Lots of benefits, including super smooth and torquey on the low end, noticeably longer run times than 2S, and cooler temps. And with the new Mamba X and Mamba Monster X having 8A internal BECs, there's no need for an external BEC unless you need different voltages to feed different components, as Robert points out. I'd suggest giving it a try to see how you like it.