CC Bec Questions?

[SeanD]

I was running two TowerPro MG945 servos off the BEC on my Moped. Apparently they were pulling too many amps so I switched to a CC BEC. I bumped the voltage up to 6.2 and with the new voltage and increased amps - what a difference!! Bionic servos - faster, stronger . . . !!

I'm pushing 6.2 volts through the TP MG945s and I'm wondering what voltages other people are safely using with these servos?

If the battery is left connected, I know that the external BEC will continue to supply power to the RX. So, it will suck the battery down to nothing (ouch!!) if left on by accident for a long period of time!! Other than being more careful about disconnecting the battery, does anybody have a solution to this?

[Col_Sanders]

I just unplug my battery anyway since the switch on my ESC doesnt work.

I'm running 6.5v to my JR650m.

[666]

From what I have heard Tower Pros can handle 7.2 volts.

[SeanD]

On a similar note:

Anybody know how many volts you can safely push through a Traxxas 2215 RX?

[mysharona]

I was running 6.5v through the traxxas rx for a while, now I am running 6.5v through a spectrum.

[Grizzly4x4]

Originally Posted by SeanD

If the battery is left connected, I know that the external BEC will continue to supply power to the RX. So, it will suck the battery down to nothing (ouch!!) if left on by accident for a long period of time!! Other than being more careful about disconnecting the battery, does anybody have a solution to this?

See the lever behind the transmission shifter?
That is a Radio Shack micro toggle switch, I just put it inline with the BEC's red wire so I can shut off the BEC. It is wired in between the main battery and the BEC. I don't unplug the batteries except to charge them.

[SeanD]

Originally Posted by Grizzly4x4

See the lever behind the transmission shifter?
That is a Radio Shack micro toggle switch, I just put it inline with the BEC's red wire so I can shut off the BEC. It is wired in between the main battery and the BEC. I don't unplug the batteries except to charge them.

I was thinking on doing this as well - but in this thread
Putting an On/Off switch on a BEC

someone said that even with a switch the BEC will still draw current (see post #4). I posted a comment for clarification but received no response (see post #6)

[Grizzly4x4]

You would need to turn off the switch on the ESC as well. If you leave the ESC switch ON, yes it will still draw current, but if you turn off the ESC it won't.
Think of it this way, the switch on the ESC was designed so that when you turn it on the ESC it gets power from the battery. Then the ESC provides power to the RX.
With the red RX wire disconnected from the ESC, the ESC switch has the same function except that power is not provided to the RX. Power to the RX comes from the BEC.

I have a Spektrum radio so the RX has a green light to show it is getting power and is binding with the radio. I flip ON my BEC switch and the RX powers up, the RX binds with the radio, and the servos work. But the throttle does not do anything.
Then I turn on power to the ESC; the Mamaba Sidewinder makes it's tones, the lights flash, and then it's ready to drive.

I have 2 rigs that work this exact same way and both of them were ran at the Scale Nats in Montana. It works....

[Grizzly4x4]

Originally Posted by SeanD

someone said that even with a switch the BEC will still draw current (see post #4).

With regards to this comment; I have not tested it but I can see how the BEC could possibly still be drawing power IF the switch was placed between the BEC and RX. It wouldn't be powering the RX but it could still be trying to convert voltage and therefore drawing current.

With the switch placed between the battery and the BEC this can't happen.

[SeanD]

Great stuff.

What I was planning on doing was mounting two similar sliding switches (BEC and ESC) side by side so that you can flip both of them on/off at the same time.

As I said in the other thread, I would place the BEC switch between the battery connection and the BEC.

Looks like a trip to electronics store!!

[Grizzly4x4]

Originally Posted by SeanD

Great stuff.

What I was planning on doing was mounting two similar sliding switches (BEC and ESC) side by side so that you can flip both of them on/off at the same time.

As I said in the other thread, I would place the BEC switch between the battery connection and the BEC.

Looks like a trip to electronics store!!

Good luck.
Check and double check your wires before powering on. I smoked a BEC because I was in a hurry and didn't double check everything.

[SeanD]

So - just to be sure.

I'll cut the red wire (stock) between the battery connection and the BEC. I'll drop in a small switch like this one:

http://www.thesource.ca/estore/Produ...roduct=2750409

which will simply make/break the circuit.

Sound good?

[Grizzly4x4]

Originally Posted by SeanD

So - just to be sure.

I'll cut the red wire (stock) between the battery connection and the BEC. I'll drop in a small switch like this one:

http://www.thesource.ca/estore/Produ...roduct=2750409

which will simply make/break the circuit.

Sound good?

Sounds perfect.

[666]

So now that we have an electronic guru here, I have my BEC hooked to the battery like most with a deans. I have noticed, running a lipo, running it this way it somehow bypasses my voltage cutoff and keeps on going. Anyway around this?

[racerx]

Patrick, I have my BEC's soldered directly to the boards of my esc's (where the battery wires are coming in) and my LV cutoff seems to work fine... Usually I notice the drop in voltage right before the esc shuts down anyway and I get the standard esc shutdown then power for a few seconds then total shutdown. Doing it this way cleans up some of the wiring and makes for a factory looking install.

[Grizzly4x4]

Pat, I think that Robb's way would be the best way to do it.

[racerx]

Originally Posted by Grizzly4x4

Pat, I think that Robb's way would be the best way to do it.

I could hear that more often!