Connect the red wire or the black wire first on battery?
 

Hey,

Do I connect the "red" wire or the "black" wire first when plugging my esc into the battery pack?

I did red wire first and then when I went to plug in the black wire it sparked for a second. Startled me and then I was concerned that I would short something out.

Suggestions?

Thanks.

I plug the negative in first, then positive. No spark.

I've had it spark both ways.
It doesn't hurt anything.

It's charging the power cap that most ESCs have on the input. It’s startling at first but after a while you hardly notice it.