Castle BEC question...

[lincpimp]

I was going to run a ccbec with a 2000mah 2s lipo to power my radio gear in one of my 8s setups. I was wondering what would happen if the input voltage drops below the output voltage setting? I was going to set it at 6.2v, as my servo seems to like that voltage. Would the bec switch off if the pack voltage drops below the setting, or would it just pass thru the current battery voltage? I would use the bec on one of the 2 4s lipos, but do not want to overdischarge one pack more than the other.

Any info would be very handy!

I do also have a HW hv bec, but it is rather large and is not very "quiet". Should not really matter as I am running 2.4ghz.

Also, if Patrick is reading this (I am sure he is!) can you consider maing a hv bec? Thank you for the rest of your products, they get a workout daily from me!

[Arct1k]

I believe it just passes though battery voltage for as long as it can - i,e, enough voltage for its brian board - which is only a few of volts IIRC.

In the event tht the input voltge flls below the desired output
voltge, the CC BEC output is essentilly equl to the input level.
CC BEC cnnot output more voltge thn the bttery it drws from.
The CC BEC will not operte or produce ny output when input voltge
drops below 4.8 volts.

I copied this from the manual,for some reason it deleted the a's.

[lincpimp]

Originally Posted by asheck

I copied this from the manual,for some reason it deleted the a's.

Thanks for the info, the a thing is funny, wonder why it did that.

I looked on the CC website and they suggested to run the bec off one pack if using more than 6s and doing it with a pair of packs 6s or below. I may do that, or use the other bec. I really hate not using a bec, rx packs of any kind are just annoying to me... More wiring, more batterys to charge and monitor, just more complexity.

But I would hate to kill my receiver and servo... At least they may be able to handle 2s voltage, but 4s will cook some stuff.

So maybe try the 2s lipo and the ccbec... I will monitor the battery and try to get a feel for how long it will last...

[What's_nitro?]

Originally Posted by asheck

I copied this from the manual,for some reason it deleted the a's.

Copy protection perhaps?

[BrianG]

In the CCBEC test I did a while back, it looks like there is a small dropout value from 0.1v to ~0.5v which increases as the load increases. Anything below ~4.5v input caused it to simply shut down.

[lincpimp]

Originally Posted by BrianG

In the CCBEC test I did a while back, it looks like there is a small dropout value from 0.1v to ~0.5v which increases as the load increases. Anything below ~4.5v input caused it to simply shut down.

Thanks Brian, appreciate the info. I will give it a try, I am pretty good with lipo, and I am sure that if I charge it every time I run the truck it will never drop too low.

[BrianG]

I wouldn't worry about it at all unless you think the input V might dip below ~5v (where you get into the region where the BEC shuts down).

[Arct1k]

Which on 2s Lipo would be no bad thing...

[sikeston34m]

Of Course the main "power hungry" thing about any setup is the drive motor. In Comparison, if you add up the consumption of everything else, I'm sure it's hardly 1/10th.

I ran a 2S 750mah lithium pack for awhile. I would only charge it up every couple of runs. You might be surprised how long 2000mah will last when put to that task.

The LVC on alot of factory pcb's is set at 2.4 volts per cell. I have a feeling with High Discharge Lipo, the recommended LVC is so high because we are drawing so much amperage from them. Then we often times want to charge them as fast as allowed.

If your running 2 batterys in series,how would you isolate the BEC to run off just 1? It seems to me that anywhere you tie into the voltage would still be the same as the total series voltage.

[BrianG]

It sounds like he wants to run a seperate, smaller 2s pack just for the BEC, but use a regulator of some kind because the voltage can be as high as 8.4v fresh.

Really, if using a switching regulator, you could use higher voltage (up to 6s). But as you go up on voltage, you don't need near as much capacity. 6s @ 333mA is the same as 2s @ 1A. The only advantage with using just 2s is that if the BEC fails, at least it will only send ~7.4v to the servos/rx and they might survive that.

[lincpimp]

Originally Posted by BrianG

It sounds like he wants to run a seperate, smaller 2s pack just for the BEC, but use a regulator of some kind because the voltage can be as high as 8.4v fresh.

Really, if using a switching regulator, you could use higher voltage (up to 6s). But as you go up on voltage, you don't need near as much capacity. 6s @ 333mA is the same as 2s @ 1A. The only advantage with using just 2s is that if the BEC fails, at least it will only send ~7.4v to the servos/rx and they might survive that.

My thoughts exactly, plus I have everything to do this, so it is "free"...