comments:
Did you try flipping the plug for the servo? brown/black usually goes to the outside edge of the receiver. The wires from the battery pack are pretty thin. From personal experience, trying to send 1A+ to or from a battery holder like that overheats the connectors/springs. Even .5A make them warm. I tried making a 2 cell pack to balance charge my 18650's with one of those using my hobby charger. I ended up getting a more robust holder that had solid spring things to hold the cells instead and it can handle at least a few amps. This is what I use instead: https://www.amazon.com/dp/B0DLGNJYCF Also, the way you have the cells wired, it looks like your running them parallel which only puts out 4.2V when fully charged. I'm not sure the esc/receiver/servo can run on 1S. You may have to at least run 2S (cells in series) to get things to work right.