Is battery drain a concern for my flashlights in my EDC pack?

I plan to keep a flashlight in a small ‘adventure’ pack along with some other nice-to-have EDC type essentials such as bandaids, aspirin, multitool, etc. I can then grab this pack when I go on quick outings such as a hike or fishing trip. This way I don’t rush about getting my gadgets and such ready and forget something that I like to have along.

I’m wondering if the flashlight will drain down since I see you guys mention drain sometimes? I will probably use one of my existing AA or 18650 lights, and use a clicky over a twisty to prevent accidental turning on, and prefer to keep the battery in the light to make it easier to deploy it if needed. Do you see any of these lights as having a drain issue?

I’m leaning towards the UniqueFire AA-S1 Osram since it is cheap but decent light and has a clip.

  • Romisen RC-G2 III XP-G R5
  • UniqueFire AA-S1 OSRAM
  • UltraFire HD2011 T6
  • XIAOZHI CREE XM-L T6

Usually it’s not a problem, since that current is too little… but it’s always a good idea to unscrew the tailcap a little, so you can forget about this issue at all.

None the flashlights you listed should have drain problems.

Expanding on what TomasVarnik said and for your reference.

If the flashlight has a clicky switch that is not an electronic (momentary) switch, it should not drain the battery at all.

Flashlights with anodized threads can be "locked out" by unscrewing the tailcap a little, this breaks the electrical contact (circuit).

High quality flashlights with electronic switches will usually have very low drain anyway.

The battery will drain itself over time, but this is very slow and will take a few years before it is drained. The time depends on the type and quality of the battery.

Have fun with your flashlights.

You’d only have problems with parasitic drain with lights that have an “electronic” switch.

Lights that have mechanical clicky switches would leave the circuit open when they’re off ==> no current flow. Then the only drain that you’d need to worry about is how much the battery capacity (mAh) decreases just on its own.

What about my assumption that a twisty could power on easier? I’m starting to think I would prefer a twisty because I want an oLight i2 due to the ability to use the clip to attach backwards on my ballcap.

Twisty lights can be turned on accidentally by pressure on the head against the body. If you just loosen the head a quarter to half turn more you can avoid this issue along with the flashlight finding a way to tighten itself in storage.

You’re right that that (power on by accident) is one of the possible problems with a twisty, but I don’t think that it’s a problem with all twisties, and probably depends more on how well the light is designed (one example that comes to mind is the original BLF specials), so it’s hard to say, generically.

I have an Olight I2eos and yes there is the possibility that if you turn it just enough that it goes off you can squeeze the light from both ends to momentarily turn it on. So yes, if you just barely turn it off and managed to wedge it into the pack so that it was squeezed from both ends and remained squeezed the whole time it could drain the battery. I’ve never had it happen though. Your most likely to get a blink as it momentarily turns on. If you twist it 1/2 turn or more you can ensure it won’t come on period. It’s what id do with a clicky as well to make sure it won’t come on accidentally.

I would say it’s much easier to turn on a clickie. It’s much more likely to press the button accidentally than to twist the head against the body. I just make sure the light won’t come on when pressed on the head after I turn it off. On mine (Thrunite TiS) about 1/4 turn is enough.