450 Spektrum Telemetry

[Dirk]

I've been toying with the idea of connecting up my telemetry. I was bored tonight and decided to dig out the Spektrum box and play with the telemetry. I can now see my main voltage as well as my RX voltage. Super cool.

Any idea as to what I should set my motor cut-off voltage to? 11.0v? 10v? Surely not lower than 10v. If I remember correctly, an 11.1v pack is completely flat at 9.6v?

 

[pvolcko]

Not sure.

Might go 10.0-10.5 if a hard cutoff. If soft cutoff, maybe 10.8-11.0.

 

[Dirk]

I am running soft cutoff. I will set my alarm for 10.8v and see how it goes. Thanks for the info.

 

[Tony]

Soft cutoff is only HOW it cuts the power. Soft will slowly lower the throttle where fast or hard will just shut the motor off. The Low Voltage Cutoff will be Low Middle/Medium or High.

 

[Dirk]

Thanks Tony. I have my ESC set to soft cutoff. Any recommendations on the minimum voltage as per telemetry to set? I see my RX voltage is running at 5.5v constantly. Sounds right to you?

 

[Tony]

Yes, the Rx voltage is regulated by your BEC. There was a red and black wire that was included with your kit that you wire into the battery (on the ESC side) to show pack voltage. I would set it to about volts and go from there. It will depend where you run your batteries down to as to what you will want it set at. And the only way to know that is to go out and fly, once you are done flying, check the voltage on your Tx and set it accordingly. Remember, you shouldn't discharge your battery more than 80%.

 

[Dirk]

Thanks Tony. I am using the included wire as you've mentioned. The other pigtail is plugged into the TM-1000 and then into the bind port on the 3GX. I read somewhere that you do it this way? Works perfectly.
Now you know why I call you Master Tony!

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Tony, you did not put in the recommended voltage in your last post to me. (I would set it to....??volts )

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Apologies. One more question. According to the 80% rule, will that mean a minimum voltage of 10.08v? (12.6-80%=10.08v), or have I gotten the cat by the tail?

 

[Tony]

It's been a long week lmao, as you can tell by missing the voltage reading. I would start at 9v and go from there. For a 3s pack that is. That would bring you down to 3 volts per cell which is pretty low.

And the 80% rule is for mah, not voltage. Basically, only 20% runtime will be left. So if you have a 1000mah battery, 80% would be 800mah leaving about 200mah in the battery. So when you charge the battery, you will put 800mah back in.

 

[Tony]

And never apologize for asking a question, that is what we are here for.

 

[Dirk]

Thanks for the help. As always, highly appreciated.

 

[Lee]

Hi Dirk, I have my telemetry alarm set to 3.5 per cell. After the flight, the batteries read 3.7V per cell, which is perfect.

 

[Dirk]

Thanks Lee,

That will give me 10.5V on my 3S pack then?