bk warrior 9918 Bec on 4s lipo
 

can I use the esc bec on 4s lipo? it's rated up to 12 cells but is it good on 4s lipo? I have a switch type external bec but it's giving a lot of cogging!

thanks guys.

You shouldn't use the built-in BEC on anything over 2s lipo or 7 cells NiMH, especially with MT/truggy/buggy steering servos. The only exception so far is the MGM controller since it has a built-in switching BEC.

BTW: what external BEC are you running right now? Cogging is hardly ever caused by the BEC...

well when I run my receiver pack it works like a charm and as soon as I switch it with my BEC it run with a lot of studders. its not really cogging as I mentionned before but anyways it runs really bad with the cheap BEC I tried to use (china made switch type)

I assume you are disabling the built-in BEC right (removing the red wire, or unplugging the black jumper)? Depending on which UBEC you are using, it could simply be bad. The DimensionEngineering and KoolFlight UBECs work quite well and have VERy little or no switching noise.

You might want to try adding a small capacitor to the BEC output. That may help eliminate any switching noise. Refer to this diagram...

You might also want to look at the electronics layout. Keep any low current wires away from the high current wires. Meaning; keep the antenna, servo, and BEC wires away from the main battery and motor wires. High current AC can cause noise to be induced into the other wires.

Thanks for your help BrianG

yes disabled the esc bec by removing the black jumper.
About the capacitor, the wiring diagram connect it in channel 3 but mine is already taken by my 1st/2nd gear servo as I still use it.
Just realised that my Bec was pretty close to my motor wires so i'll try another position maybe that will fix it. If it still doesn't work i'll blame it on the cheap chineese unit I used! lol

thanks

well, it looks like the cheap unit is ok after all, i moved it up front and away from the battery/motor wires and it works fine now!

Cool, so it was simply just noise after all.

Looks like it was, thanks for your help