Don't do it.
I have a 1300mah Ego that stopped working. Took it to an electrician friend of mine and he rewired it with better quality wire and it worked good for about 3 days, now it's dead again.
I took it apart just now and there used to be a piece of rubber that sat on top of the battery, it's still there was melted. One of the new wires burnt into and there's melted rubber all inside it now.
Lesson learned, I'm just going to buy a new one.
I have a 1300mah Ego that stopped working. Took it to an electrician friend of mine and he rewired it with better quality wire and it worked good for about 3 days, now it's dead again.
I took it apart just now and there used to be a piece of rubber that sat on top of the battery, it's still there was melted. One of the new wires burnt into and there's melted rubber all inside it now.
Lesson learned, I'm just going to buy a new one.