Are you talking about lights with some tail light that stays on or something else?
some lights keep their microprocessor on, just to monitor the switch
better designs will ‘sleep’ the micro in a lower power mode, and pressing the button will cause it to wake up and start running the light, using more computing power
as far as specific lights, you would have to know about the design to really know where the drain might be, and the reason
older controllers may not have supported ‘sleep mode’, or the programmer didn;t bother to use it, or it could just be a circuit error, or as you said, any LEDs that stay on like in the button
wle
Lights with a side switch consume a tiny amount of power, even if the light is off. With an old school clicky switch, the electric circuit is open when light is off, so drain is zero.
But this is not the case with lights like the TN4A. One problem is that the parasitic drain value of a light is rarely specified by a manufacturer. Another problem is that the parasitic drain value can vary significantly from sample to sample, even though the light output is identical.
So basically the parasitic drain is one big unknown when purchasing a light. And this is a bad combination with a light that you want to leave in the glove compartment and forget.
An easy remedy with a light like the TN4A is to slightly unscrew the battery tube, so you have an open circuit for zero drain. But you must keep this in mind.
I agree with all comments about ” Alkaleaks ” These type of batteries leak over time. Shelf life is minimal. If you value any of your flashlights do not use them. I will give you some examples below of my personal experiences of ” Alkaleaks ” I love all my flashlights whether high end or economy class.
1. My Police Security Silver 6 D flashlight leaked right from factory. Brand spanking new. I opened tail cap because it would no light up. Corrosive battery acid ate into wall lining inside damaging. Thank god only 3 of them leaked as I was able to remove them. BTW, this flashlight is extremely hard to find and not in production anymore.
2. Maglite 3 - 6 D flashlight. Same scenario as above.
3. Nitecore E41 4 AA same problem
4. Maglite XL50 3 AAA same problem.
As you can see Alkaleaks are very bad.
I will use them only in cheapo, or extremely low quality light. I pick up free battery packs from Harbor Freight for those purposes.
Use recharge ones : Energizer, Eenolops, Duracell, Lithium, etc….
It doesn’t pertain to the thread many blf threads get sidetracked. But it’s his thread to side track I guess. He just noticed my signature. I’m about to start a thread soon. Bringing all the snow flakiness to everyone’s attention in my 1000 post giveaway. It’s going to be a unconventional giveaway to say the least. I’m interested to see if the snow flakes will cry and ruin it for everyone. I’ll drop a hint it’s a light with a dedomed emitter that can’t be purchased anymore and people I’ve seen offer 5 to 10x the cost of the led. So it’ll be ashamed if people and their high estrogen ruin it. But it may not be the snow flakes fault completely. Soy is in every single processed food we eat. 99 percent. Soy significantly raises estrogen and lowers testosterone. Also the chemicals in plastic which is in everything we use in day to day life. Break down into estrogen into the body. So all these “men” in their feelings might not be all their fault completely. Or maybe I’m just a hard ass Marine that’s seen and done things people can’t imagine and words on a screen don’t bother me so much. Only person who can hurt me with words is my wife.
If you’re worried about an emergency situation where you might have to make do with whatever cells you can find, I would suggest that you consider having two lights: one light that takes 3×AA or 4×AA, and a second light that takes 1×AA.
That way, if you only have one cell, you can still use the 1×AA light. If you have 3 or 4 cells, you can use the larger light for higher efficiency and access to higher light output (if you need it).
Efficiency is especially relevant with alkaline cells, because the boost driver in a 1×AA light trades current for voltage - it has to draw more current at the input to get more voltage at the output. That’s about the worst thing you can do with an alkaline cell, because its high internal resistance will cause its voltage to drop at higher current, so the driver needs even more current, which causes the cell voltage to drop still further, and so on into a vicious circle. NiMH cells and lithium cells are much less prone to this effect.
I would strongly recommend avoiding alkaline cells unless it really is an emergency, because of the risk that they will leak.
My advice is to put Eneloop NiMH in both lights, with an unopened pack of 1.5V Energizer Ultimate Lithium primary cells in a Ziploc bag stored next to each light. That way, the lights are ready for use, and you have a set of long shelf life cells ready as a backup.
Swap the Eneloops for a fresh set once a year, as a “belt and braces” precaution. They do hold a charge for up to 10 years, but there’s always an outside chance that even the best quality product might fail on you. It’s a fact of life that nothing’s perfect.
Steer clear of lights that take more than 4 AA cells, unless they can be used with a partial set. You might not be able to get your hands on 6 or 8 AAs at once in an emergency. For example, I have an old Fenix TK41, which is an 8×AA light, but I’m fine with that because it can run on 4×AA if necessary.
Alkaline are yuk.
Lion and solar charger. win.
Make sure to get a light with lockout tailcap for 0 parasitic drain.
Impressive.
Thanks!
Yes my tn4a has bad drain in it. I’ll put batteries in it. Come back maybe 5 6 weeks give or take and it’s on the red. It will still run for awhile but I can’t get into turbo. So now I leave it backed off half a turn or so. Now my nitecore ea41 can sit for twice as long without having low barriers. But as you said it can vary sample to sample. I don’t lock it out physically or electrical it can do both. I can’t remember if the tn4a has a switch lockout
“pertains” was maybe the wrong word but I couldn’t think of the right word, I didn’t mean sidetracking/derailment whatever, I was curious what he was replying about here, thought it was odd for that to just come “out of the blue” but I never noticed your sig so that explains it, thanks.
Works for me. In my car I have, besides a thrower in the arm-rest, a Nitecore MT22A with Eneloop Pro’s in my glove box, and an EagleTac D25C-ti with a CR123A in my Bug-out-Bag. Plus some spare batteries, and a charger, of course. Don’t leave home without it :smiling_imp:
Thanks. You can filter by any number or combination of fields.
This. 
Doesn’t matter if you use a “name brand” like Enerleakers or Duraleak, they WILL leak. Great way to absolutely positively ruin a light, as I’ve done, unfortunately, several times. Even my TK4A now has a brown “nipple” inside where the alkaleak took a dump all over it. Goodbye beautiful little EA01, when a lousy AAA exploded inside it.
You won’t have to worry about zombies when your alkaleaks will put you in the dark.
Use alkaleaks only as a last last last resort, and toss them as soon as they hint at being near end-of-life.
Now, the lights… Yeah, a nice Thorfire TK4A / Sofirn SF11 are veryveryvery similar, right down to the UI. They take 4×AA in series, and will put out around 1000 lemons on high, rivaling even 18650 lights.
They use e-switches, do not physically lock out, so only load ’em up if/when you’re going to be using them. Else you’ll forget about it in a car or closet, and goodbye light, when those hateful little batteries gleefully destroy your light’s innards.
Naw. You just give her the alkaleaks, you keep the eneloops, then when the SHTF, grab your lights and just toss her to the zombies. 
Generally, the more expensive the light, the lower the parasitic drain will be for its electronic switch. But the parasitic drain can vary widely. I have measured some of my lights with as little as 2 microamps of drain, and others with over 1 milliamp.
Most Zebralights are among the lowest drain, and you can essentially ignore the drain completely. It’s lower than the self-discharge of batteries, and would take over 20 years to drain a battery.
Some of my cheaper lights have a parasitic drain that depletes them in just 2 months. This makes them essentially useless for storage with batteries in them.
If you’re storing a light for long periods of time for emergencies, then get one with a mechanical tail switch. That way, it will have zero drain.
I don’t use my aa lights much and I have a pile of eneloop pro, Amazon pro, imedion, and Duracell lsd. I try to use them a little more now. But sometimes I’ll leave the tn4a screwed on so it will drain the batteries. So I can rotate in another set. So they don’t sit for a year and not be used. If I know I’m taking my kids to the park or something soon I’ll back it off a half turn. But with so many lithium lights. Much smaller lighter and more powerful I have to make myself use them. But I keep them just incase. I was ground zero for Katrina (literally the east eye wall hit Bay St. Louis). Lithium batteries would have been impossible to use or charge. But aa batteries I could have easily scavenged. All I had was what I could throw into a single dufflebag
Another 4xAA / 4x14500 option: Manker MK41.
Or just loosen the tail cap, although I know it’s easy to forget.
Well well well. The old what to do in the end of times question. A lot of answers here. Some good , some uh, anyway. Not sure what your end of days is, but I am gonna tell you right now if it has any thing to do with Z people, then throwers our OUT. Z people are attracted to light. Not really attracted to light, but they soon learn that light means lunch. Well know Fact. You don’t want them coming from the nearest city, because you wanted to light up something half mile away. They are slow but determined, even after you scan you camp they will remember where the light was last. You wake up surrounded (been there). Your far better off using light and sound discipline and moving during the day or just waiting them out in your bunker. Yeah, just wait them out.
Not sure what your cell of choice is. But there are many 18650 lights will also run on 2x Cr123 primary cells. Some 14500 lights will run on NIMH, L91’s , Alkys and others. Some pointed out solar, and a charger, yep get one. Or if your going to be car based like your post mentioned. Then you could charge while driving or just get a spot light that plugs into cig ligher.
If you still want a thrower for end of times without the Z people. There are several that will do primary cells also. I would stay away from multi AA lights.
So what you need to take from all of this is
1. Have a edc light in your rotation that works with primary cells also.
2. Use it in your rotation, or as your primary edc. If you like it. Get a spare. I don’t want Z people getting you because you turned
on your never used end of times light on in TURBO.
3. If you must have a Thrower. Get a single 18650 that will also run 2 x cr123 cells. Buy a stash of 123s For when you cant
recharge.
4. Do some runs on primary cells to see how many you think you will need. How long they hold Hi. etc etc etc.
5. If you go with AA go single cell. Get yourself a stash of lithium primary cells. You won’t need to buy Alkaline cells. They
should be easy to find. After all no flashlight lover would ever ever put a alkaline in there lights.
6. Learn to harvest laptop batterys.
7. Buy some kerosene laterns, harpoon, and a boat. We might be burning whale oil before things get back to good.
Hunker Down or Lite and Fast
That’s a good alternative for us, but for non-flashaholics, they’ll just think the light is dead.
Awhile ago I lent someone a AA light, loaded with an Eneloop. The next day, they returned it, and told me the light was broken because it would only work in low mode. It worked for awhile, but got hot, and then stopped working. So, I took back the light and checked the battery: 1 volt. New battery, good as new.
I’m just glad they didn’t throw out the light. Or, if they were only slightly more clued-in, they might have thrown out the Eneloop and replaced it with an alkaleak.
I also lent someone (briefly) an 18650 light some time ago. For some odd reason, they first opened the battery tube and looked at the battery (a Samsung 30Q). I guess they were curious about the light? Anyway, they thought I was messing with them, because why did I put a tampon in the flashlight? Okay, it was only their initial reaction until they realized it was just a big pink battery, but they had never seen one before so were stumped such a battery could even exist.
Never underestimate what some users will do.
My general rule now with lights is to never lend someone an 18650 light unless I tell them never to open it, and give it back to me as soon as you’re done. I swear some of my friends would stick the battery up their butt and give themselves a shocking surprise.