What does 3-18V mean exactly?

I just got on the mail an Ultrafire P60 XPG R5 450lm dropin from Fasttech. My thinking was that since its 3-18V, it has some sort of overdischarge protection and it will turn off when voltage drops to 3V. At about 3.2V the light has started to noticeably get dimmer, however the light is still on and just measured the battery at 2.8V (?!).

that is the input range. you can use 1-4 li-ion cells with it, or any type of cells that add up into that voltage range (as long as they are the same chemistry)

So possibly I can totally run down the battery to 0.something V? :slight_smile:

i dont know about 0v, but you can run it down enough to ruin a cell

Thanks Pulsar, I guess I need a different drop-in. :slight_smile:

you could swap the driver out to a nanj or similar

link to driver?

I have this. Can I use this driver?