My friend and I were just soldering Deans on our batteries and Castle Sidewinder ESCs just last night. I have a Hakko iron, (pretty certain it is the 455-16 40W / 1110 F). First time soldering deans. Anyway my friend managed to overheat one of his deans plugs so we knew the iron got plenty hot!

We had difficulty melting the solder on the pre-tinned battery leads. Yeah, could really feel the heat travel up through the wires. I pretty much just tinned the deans plug and let the solder on that flow onto the ESC battery leads.