Appreciating all the feedback here. As long as I can still use AAs as a backup (or lazy) option, then I think I'd like to give rechargables a try. The Fenix sounds good. Rechargable for day to day use, AAs in a drawer for when a hurricane blows through, I forget to charge, the batteries lose capacity over time, etc.It does look like rechargables have come down a lot since the last time I looked (or, again, I just did a lousy job of looking). I see you recommending Liion. I feel like eneloop used to be the going rec. Has Liion overaken them, or should I look at them also?
It all depends what you want from a flashlight.
It looks like you got a few good answers for your question.Something I did not see mentioned, but might have missed, are rechargeable batteries with charging ports built in. If you like AA, there are both Li-ion and NiMh with built in usb-c recharging ports. I like them especially for travel, because I get the benefit of rechargeable batteries others mentioned without needing a separate charger.
I went the rechargable way just a fortnight ago.This after always relying on batteries.I needed max. power in smallest possible size and that pushed me over.Eventually I chose the Nitecore TM12K. I've used it according my original use case, it does what it says on the tin and so far I haven't even charged it yet.So, happy camper me, guess we will see if that stays the same in the coming months and years.Lähetetty minun SM-T515 laitteesta Tapatalkilla
That is awesome small powerhouse and looks great but also pricetag is awesome.Only Tools Matters
True, those are handy but rechargeable AA usb-c also have bad habit to die, without warning since it gives from start to end 1,5v current (thanks to current regulator) if there isnt something to show capacity from that we come to capacity what is smaller than regular chargeable AA and depening quality of battery (what company made them) real capacity might be much smaller than stated.Real advantage comes from steady current from start to end (even if they die suddenly) meaning devices like flashlight, light doesnt fade but keeps it same amount lumen all the time until battery dies.Like Sos24 mentioned those are handy on a trips where you can charge them allmost anywhere (if you have cable with you) and home if you have misplaced batterycharger.I have used these kind but those broked after 2 months, then i used batteries lot and thought those would come handy, first those were handy but some of those are badly made and usb became loose until it was point of break. Whole usb part wobbled and didnt charge anymore. So avoid those with USB-A head.My friend has 18650 batteries with usb-c port, it have come bit loose but still works after 1,5 years of use ( he use them on vape so he charges them regularry)(Image removed from quote.)Only Tools Matters
I have the ones with the port built in. The Acebeam 14500 and Fenix 16340 have worked well for me. I have also used Pale Blue Earth AA and AAA for about a year. Originally they had usb-micro ports but switched to usb-c not that long ago.
I may need to try those usb-c Pale Blue AA batteries, i could use those on console controller batteries ( i have rechargeable batteries in those but its diffrent kind)Only Tools Matters
The numbers (21700 vs 14500) refer to the physical dimensions of the battery, correct? I don't need to worry about "picking" the optimal one, I just use the one that fits?
I’d say this is partly true, as many of the batteries are physically different sizes and many of the numbers do refer to physical dimensions. However, there are some important caveats. First, it is always wise to consult the owner’s manual for your device to determine what batteries are acceptable to use in it. For example, AA and 14500 batteries are basically the same size, but because the voltage is different, AAs shouldn’t be replaced with 14500s unless the device is designed to handle the higher voltage. Second, even with a specific battery size, there are different options: protected vs. unprotected, energy capacity, rated cycles, rated shelf life, etc.P.S. I agree with those who have pointed out that batteries with built-in charging ports are more convenient than needing a separate charger, but my real preference is USB-C charging built into the flashlight. No messing around with separate chargers or proprietary connectors, easily available spares/replacements, fast charging without even needing to open the light…
Even better option for usb-c IMHO is magnet charging it eliminates port damages even with cost slower charging.
I know I’m in the minority here in this, but I just don’t like rechargeable lithium batteries for flashlights. Even if the chance of thermal runaway is small, it is literally a pipe bomb in your pocket. They’re sealed tightly enough the best case is it blows out the lens/optic. Worse case is metal shrapnel. For my needs, I don’t need the additional light output enough to offset the risk.
Of course, you pays your money and takes your choice.To quantify the risk, though, we’re talking about a catastrophic failure rate of quality Li-ion cells that is on the order of one in ten million.
I agree the risk is probably low overall, but I’d be curious where the 1 in 10 million number comes from. In my experience it seems like it is higher. There are several consumer devices that have high rates of catastrophic battery failure: EV batteries, cellphones and laptops (so-called “spicy pillows,” which if happened in a light could be very bad), and battery power tools. All of these are cells using smart charging and various kinds of protection.I’ve personally had a work laptop go “spicy pillow” and have had a dewalt li-ion rechargeable battery vent.
I don't think I've ever heard of a torch exploding like you describe, I'm... not even sure that's possible? But I do notice some stuff about your examples:"spicy pillows" - Arguably the most notable here is the Samsung Galaxy Note 7, it was a failure of the battery manufacturers (there were two, with different problems), but it wasn't a problem of battery chemistry. Phones and laptops are arguably the most problematic here because of their form factor and the intense heat they can, very easily, be subjected to.EV batteries - As far as I'm aware, EV batteries are like old laptop batteries, basically just a big ol' case full of smaller Li-ion batteries. I'm going to assume that this makes the failure rate more complex when each EV has however many individual hundreds/thousands of cells within it.As a bonus I'll throw bike batteries in here because a common issue is a combination of using the wrong charger and people wanting an E-bike cheaper, so getting something with too many load-bearing corners cut.In use in a flashlight there doesn't really seem to be an issue at all.And some quick research shows that lithium primaries seem to be the more dangerous of the two anyway?I've owned and used Li-ion cells in lights now for over a decade and I've never experienced a failure, catastrophic or otherwise, and all the cells are actually still in useable condition. If the risk were really anywhere significant, it would not only be more talked about, the tech wouldn't be so wide spread. I'm going to go out on a limb and say that the likelihood of death through car accident and flying are probably higher.
I agree the risk is probably low overall, but I’d be curious where the 1 in 10 million number comes from. In my experience it seems like it is higher.
I’ve seen it referenced in multiple articles by “experts”:https://cen.acs.org/articles/91/i6/Assessing-Safety-Lithium-Ion-Batteries.htmlhttps://polarium.com/insights/safety/https://batteryuniversity.com/article/bu-304a-safety-concerns-with-li-ion