"King Kong 3000"
is a joye's product and it is based on joye eGo
electronic, it is big eGo.
It holds 18650 li-ion battery and it works with protected ones and unprotected.
Some of protected batteries will not fit in body cause of bigger
circuit board, so its better to use unprotected. It has build in
protection so no worry.
It is not an "eGo N" what ever it is.
As I said earlier it has joyes electronic so it will give you
constants 3.4-3.5V voltage from start till discharge, as joyes eGo do.
No 4.2 to 3.4V as cheap products does.
It can be charged by standard 420mA eGo charger or you can charge it
by dedicated 18650 li-ion charger.
It has PWM (Pulse-width modulation) so it is pumping voltage really good.
It isn't variable voltage as provari :> but people in Poland found
that it works on two lifepo4 batteries giving almost 5V. But watch
out, nobody knows how long it will work on that voltage!