electronicNerd NO!!!, A fully charged Lithium-cell is 4.25 volt! Further more, when it's half discharged the voltage will drop below 3.6 volt. Fully discharged a Lithium-cell will drop to 2.5 volt. You will have to make a constant-current controller and limit the CURRENT to max. 6-700mA! Do not think about voltage just be sure it is sufficient high to drive the current-controller. A simple current contoller can be made with 4 components, a transistor (that can handle the current), 2 resistors and a small red LED with a voltage-drop as low as 0.5 volt :-) :-)

electronicNerd Use a resistor in stead of cutting a diode, If the chain is using that much, they have forgotten the serial resistor! Use a resistor approx 10 ohm, gives you a comsumption of about 250mA. Be carefull with the wattage of the resistor as 10 ohm will produse about 0.5W heat! Or as I do: Reduce the voltage to a level about 3.8-4.0 Volt and adjust the resistor according to the lovered voltage.

electronicNerd The battery is only a +400mA battery, not 3000 as stamped. Tested 2 different lamps and the summa-current put into the battery was 428mA and 431mA