Spark Suppression

[esoarer]

My new multi-rotor platform uses a 6S Lipo.
I get a heavy spark on the bullet connectors when I connect up as the initial surge is going out to 6 x 40A ESC';s and I guess into the extra capacitors I have fitted to the power line into each ESC.
It doesn';t seem to be causing an RF problem, but the connectors are taking a pounding!
I';m no expert, but I am I right in believing that normal spark suppression techniques using a resistor and capacitor could resolve this problem? Does the attached pic provide the info I need?

Thanks for your help!

[ChrisH]

I get big splashes from the Deans connectors on my 3S powered quad every time. My new build uses XT60 connectors on a hex and minimal splashes at any time.

It varies depending on the connectors you use! 

Don';t know if the spark suppression route would work for such a powerful but short pulse of power. But that';s what it should do...

[ChrisH]

In case you are interested Jumpy07 (Craig) has a very interesting guide on battery connector types at http://www.multi-rotor.co.uk/index.php?topic=1032.0

[esoarer]

Thanks for the useful response !

After further research and contacting a flying buddy who knows much more than I do - I HAVE THE ANSWER !! As Below:

"The spark is due to all the electrolytic capacitors around the system needing to charge when power is applied and you cannot suppress it as such.  (Suppressing techniques are designed to absorb the spark into the capacitors of the suppressors).

The  solution would be a two stage switch on.  In essence this requires a double connector arrangement and a series resistor.  First connector connects to the batteries via a resistor and the capacitors then charge up through this resistor.  A short time later the main connector links across the resistor as this no longer has to carry the initial charging current.  This is effectively what is often done in industrial motor controllers.

Good news is that you do not need to build all this.  Take a look at Jeti Anti–Spark  connectors available from Electric Wingman, 4mm rated 75A http://www.electricwingman.com/jeti-anti-spark-connectors-4mm.aspx and 5.5mm rated 150A .  http://www.electricwingman.com/product.aspx?product=2346.  They work by using the technique described above with the resistor built in to one of the connectors  (connect this one last).

A description of operation here  http://www.modellhobby.de/Electronic/Electronic-Speedcontrollers/Jeti-anti-spark-connector-set-5-5mm.htm?shop=k_staufenb_e&SessionId=&a=article&ProdNr=058ABL55&t=9&c=22&p=22

I hope that info may help anyone with the same problem as I have (had!)

[Toledodave]

This cured my problem. Battery is always connected along with constant ground and only connecting the red positive to power the copter rather then both positive and negative everytime. I bought this one for couple bucks. But is easily made.  Also nice during trouble shooting you can teather a lead line to it like a rip cord for an emergency shut down then remove for flight.