What battery does my laser need?

[Benm]

There should be a driver in the laser that adjusts the battery voltage to what the laser diode needs, so the battery voltage could be lower or higher than the diode voltage, depening on design.

If reviews indicate that it overheats on 3.7 volts that's probably reason enough no to use those.

18650, like 16340, is just an indication of size (18mm diameter, 65mm length) but not of voltage. Usually 18650 cells are the 3.7 volt nominal voltage lithium rechargeable batteries that were very common in laptop battery packs.

There are, however, 18650-sized cells on the market with the lower 3-3.2v nominal voltage and LiFePo chemistry.

 

[GSS]

See answers in red.

I salvaged some S code LG 18650's from my laptop battery, which are 2200mah but a lower I believe 5A.
In general what might I see running 2 of them in say a 2W M140 at 1.8A?

 

[lasersbee]

Laser 303 is generally equipped with 1 x 18650 battery, i think your laser is like this: 303 Laser Pointer 100mW 5 in 1 Green Beam Light Pen Burn Match

Wow... that is expensive for 100mW...
Is it gold lined.
The OP said he paid $20. :thinking:

Jerry