Back in the Dark ages BHPLED (Before High Power LED) 🤣🤣 flashlights were simple.  Switch on and turn electricity into fire in an incandescent bulb.  

In the current Enlightened Age (see what I did there😉) we need a little more finesse. 


That’s where the driver comes in. The driver is the brain of your flashlight.   


Drivers take the power from the cell (battery), regulate it and send it to the emitter (LED) to make light. 


You'll hear terms like 7135, FET, PWM and firmware bandied about by the driver experts. Let’s break it down. 


Let’s start with firmware. Your driver has a computer built into it.  It controls things like all the different brightness settings, watches that the temperature doesn’t get so hot that it damages the electronics, monitors the voltage in the lithium-ion cell so it doesn’t over-discharge and cause an explosion hazard, memory options, strobe, etc.  - Everything that makes your torch function. 


I should mention that not all drivers have all these functions. Of particular concern is the low voltage detection. Low voltage protection stops a cell from over-discharging. Over-discharging is really bad for lithium-ion cells.  Best case, you need a really good charger to resurrect the cell. 


Worst cases get progressively worse.  Best of the worst is that your cell is ruined by the over-discharge.  Worst case is that it bursts into flames and explodes.   


It’s very important to know whether your driver has this feature because it dictates what kind of cells you can use. If it doesn’t have over-discharge protection, you can only safely use protected cells.  


If it does have protection, then you’re good to go with anything that will fit. 


Got anything you want to know about flashlights?  Let me know in the comments and I'll add it to my How to Speak Flashlight list.