A couple of weeks ago I was prevented from flying "one last time" because my 4mm bullet connectors sparked so much that they damaged the end of the connector on the ESC enough to stop me connecting another battery. I replaced all my connectors with shiny new ones and went flying yesterday. The first battery sparked and damaged the connector again, preventing any flights with that model. I need a way to prevent that spark...
I've added a 2mm female connector to the negative lead of my ESC. I've then made a harness that has a 2mm male connector on one end, a crocodile clip on the other, and a resistor inbetween. The resistor is much bigger than needed, but it is one I had. I'm sure that any 1/4 watt resistor of about 10 ohms will do the job. I'm sure I've got a load of small resistors somewhere, but could not find them.
To make the connection without a spark you need to connect the positive battery lead to your ESC first. Then connect the harness with the 2mm plug and the other end to the 4mm male on the battery. Now slide the male into the ESC female before removing the crocodile clip. No more sparks and long life to my connectors.