Question about powering a laser module...

[jason 77]

I have a question about the laser module pictured below and its kind. The specs say that it requires 3 volts, can I use a Li-ion battery like a 18650 to power the laser or will the 1 to .7 volts extra be too much for the driver on it's board? Does anyone know if the circuit on these lasers is just a Constant current type or if it is something a little more complicated? I am used to dealing with high powered LEDs and really don't know what it takes to properly power up on of this laser diodes?

[FRITZHID]

that laser is a CC/CV controlled module. the little tiny POT could be used to tune down the power to the diode if you wanted to use a higher voltage source HOWEVER it may not be tuneable to a low enough power. each manufacturer has their own set ups and almost all very in specs enough that "guessing" is risky. i'd put $ on it would be ok to run that module on an 18650 but be sure to tune down 1st THEN connect it and tune up slowly back to its base power, which you should test with a 3.0v source first. the brass housing is of sufficient heat sinking that there should be no issues with diode heat build up, especially with short bursts at high power. if you see beam divergence or "splitting" at longer distances, beam suddenly drops it power or brightness or color shifting, stop use immediately and tune down further. these are signs of diode degradation and x-tal fracturing due to heat.

[bshanahan14rulz]

I have been running a green module designed for 3V on an 18650. The driver was modified by adding a silicon diode inline to drop some extra voltage. The diode in my build ended up replacing the switch, since it was going to be externally switched anyways. Basically, put a diode between your battery's + and the input of the driver, where the red wire connects. That should drop about 0.7V. You are still taking a risk with the last ~0.5V that a Li-Ion can offer (4.2V fully charged), but mine has been working fine for a while now.