I have a 3.7 2200mAh Li-Ion battery. Is it ok for cree xp-g R5 led

I was thinking about making a light using the Li-Ion 18650 battery. Can I use it without a buckpuck as the voltage listed on the cree xp-g R5 spec sheet states the upper limit is 3.7. Do you think I'll need a currrent limiting resistor or can I go without one. TIA

evs said:

I was thinking about making a light using the Li-Ion 18650 battery. Can I use it without a buckpuck as the voltage listed on the cree xp-g R5 spec sheet states the upper limit is 3.7. Do you think I'll need a currrent limiting resistor or can I go without one. TIA

Click to expand...

Keep in mind that when the battery is fully charged the voltage is 4.2 volts

OH and :welcome:

no you can't directly connect that LED to the 18650. Yes you will need a resistor or driver circuit in between to regulate current/power to the LED.

Id like to max it out at the 1500mAH that the specs say is the max but I was looking at the buckpuck that pushes out 1000mA but Im not sure the battery will be pk with it. Since the voltage on the battery fully charged is 4.2 volts and the 3021 needs a min of 5v. Is there a buckpuck that I can use with a 3.7-4.2v input with a constant 1000mA output.
If I do the math for the resistor Im getting .4ohms Does that sound about right? What wattage would it need to be?

Thanks (and enjoyin the forum, good stuff here
evs