Resistors are not recommended for regulating current to high power LEDs for two very important reasons.
First, resistors are not able to respond to changes to input voltage levels, which will cause very large variations of input current to the LED. Over-driving an LED with too much current, even briefly, will significantly reduce its operating life and even lead to total failure within a few seconds. This problem is especially acute for battery power sources as the voltage level of most batteries will vary significantly over the charge/discharge cycle of the battery.
Second, resistors are very inefficient regulators as they simply turn excess current into heat. This means that you need to use high wattage resistors and provide some means of cooling the resistor.
To protect your LED investment, you should seriously consider using a current regulating driver that is specifically designed to regulate current for high power LEDs.
Current Regulating Drivers:
- Are extremely efficient - unlike resistors, they run cool.
- Provide precise current regulation and protection regardless of the input voltage.
- Make it easy to dim the LED with just a potentiometer.
- Are available with 350mA, 700mA and 1000mA outputs.
- Are just as easy to use as a resistor.
You can learn more about the LED drivers that we have available here.