No warning. These batteries were the ones that came with it, do they come with batteries? I don't remember. They either came with it or they were new surefire batteries I bought a year ago. Anyway, not even 3 months on these batteries. I feel like there is no way I put 1.5 hours on these batteries in that time, just flicking it on for a second or two here and there. No real use. So last night I flick it on and it flashes then turns off. With my m600 I notice it get dimmer (this is on the 18650) over time. I didn't notice it with the X300.  Just went dead.

Is this normal? Maybe the batteries were no good. Do I have to just change these every two months?

I had the same thing happen to me yesterday. I use only once in a while. I turned it on and it flashed, then dead. I thought I broke it. It went from blinding bright to nothing. I put in new batteries and it was fine. Do all LED lights do this?

Interesting.

To answer that last question, no. Typically and unregulated LED will only be brightest on fresh batteries, and the light will dim as the batteries drain down.

A regulated LED, which is one with a mechanism that regulates light output, will have a constant output for the life of the batteries. Typically, in my experience anyway, regulated LEDs usually have a “replace batteries” mode when the batteries are about to die which is much dimmer so you know to change them and also aren’t left in the dark.

I do not know if the x300s are regulated, I can’t find anything about it.

X300’s and X400’s are pretty notorious for draining issues. A lot of fanboys will deny it but about half of the ones I’ve had have had bad draining issues. The X400V’s are so bad that I never leave batteries in them. My two current X300U’s don’t do it too bad but both I can put a set of batteries in, never turn on and 6 months later they’re dead just from sitting in the safe.

Streamlights on the other hand I have never had an issue with. I’ve got some TLR-7A’s and TLR-1 HL’s that don’t get used too often with batteries that are two years old and are fine.

That’s so odd. My guess is this is an issue with the switch, it must not switch off entirely. Idk how it would drain the batteries otherwise.

Maybe I’ll pick up the rechargeables. Charging batteries every two months is a bit easier to stomach.

I think I’m running close to a year on one set of batteries. I’d call surefire if I was you

My agency authorizes X300s among a couple other options, and we typically see the worst battery life coming from the SureFires.  I’ve had substantial drain issues from two of the three X300 models I own.   I have two X300Us and one of them will go the distance and the other will kill batteries pretty quickly.  It’s one of a couple reasons why we recommend our recruits buy the TLR-1HL for their pistols (we issue Sig P320 RXP w/ Romeo1 but recruits have to buy the light and holster) instead of the other options like SureFire and Inforce.

SureFire are also assholes.  We got into it with them this year at SHOT.  We (delegation from my large metro LE agency) tried to talk to them about something and they wouldn’t talk to us because they were only doing reservations and they were booked full before we found this out.  They full well knew who we were and still refused to let anyone talk to us.  So we talked shit to them and thanked them for allowing us to cross them off our list for agency purchase of 500+ WMLs.  They didn’t seem to give a shit despite the fact that they’re financially struggling pretty bad right now.  We’re more than happy to go drop $100k+ somewhere else and let them continue to circle the financial drain.

Interesting....I have 2 of the older lum ones & a newer 200. Haven't noticed this. The 2 older ones have sat in the safe for over a year.