grounding

[urbs00007]

have a slight problem with my radio system. I'm using graupner 4 channel with telemetry. temp sensor works fine. however voltage sensor only reads up to 25 volts and I am running 10s, so I decided to read 1 cell off the balancing lead and use that as a voltage source. my problem lies with grounding my external bec battery, which is powering my receiver. that battery needs to share a ground with my main batteries because I need to ground the battery that i tap off the balancing lead. can I just run a ground wire from the esc negative to the bec battery negative ? all this is because the telemetry sensor lead to voltage source is a single red lead.

[CraigP]

Hey Urbs,

You can if your BEC is not a floating type. Most aren't, but some of the higher power switching BEC's are floating. The ESC ground is the negative rail for the motor phase switches, so it is system ground.

Take an Ohm Meter and check resistance from the negative power in on the BEC to the negative power out. If it reads a short, you're good to go!

Note that the ESC ground is noisy, if your readings are really noisy, you may need a noise filter on your Red and black lead going to your voltage sense, hope that helps!

[Prodrvr]

Why are you trying to read the voltage of the main pack? Just curious. And the directions say the wire from the voltage sensor must be attached to the main pack power lead.

[CraigP]

I've done that to compare voltage at the esc... Looking for power robbing voltage drops. Not sure what Urbs's purpose is...

[urbs00007]

I've done that to compare voltage at the esc... Looking for power robbing voltage drops. Not sure what Urbs's purpose is...

hi everyone. I ended up powering my bec off one off my 5s packs. now the voltage sensor is grounded thru the receiver. all set. thanks

[CraigP]

Good play!!