Do you prefer tail lights with built-in, USB-rechargeable batteries, or ones with standard replaceable batteries (AA/AAA)? The built-in, USB-rechargeable batteries are certainly convenient, and I'm pretty sure I'll break or lose a light before the battery fails, but it also seems like an LED is going to last a lot longer than the battery so if I really want to minimize long-term cost and plastic production I should use rechargeable AA/AAA batteries. The ones with built-in batteries do seem better sealed against weather (unsurprisingly). Any other reasons to prefer one over the other?

I prefer lights that use standard AAA batteries. I use the rechargeable Panasonic Eneloop cells with a smart charger. Carrying a spare set of batteries means that there are no worries about a dead light. Can't do that with internal-rechargable lights.

Can you find the same exact light with wired in batteries and it's other version with replaceable batteries? I don't know of any, so I'd probably weigh my choice to other things about the light. Otherwise we get into manufacturing quality and design compromises.

All said, I've had my little daytime Bontrager Flares since about 2017. The internal re-chargeable battery still last longer than it takes to do a century ride. So what more do I need? More convenient for my use to simply plug in a USB cable than to have to remove them to charge. Though perhaps some have replaceable batteries that can be charged in place.

Most of my blinky use has been commuting (until the last few years). It's easier to keep a pair of spare batteries in a pannier and pop them in when the light doesn't work when I'm ready to head home than to recharge through USB.

I much prefer an internal USB-rechargeable battery for all my (way too many) bike-related devices.

I think newer lithium batteries have longer lifetimes now. Better battery design and manufacturing methods?
My old Dinotte lithium battery started getting short run times after just 2 or 3 years. But my current Cygolite blinky headlight has been holding good run times for 3 or 4 years. I run it on single flash on every ride, and charge it every two or three rides.

Same with my Makita 18v drill batteries. These are still going great after four years. (it's way less usage than a bike light, but my older nickel metal drill was useless after just 2 years.)

Tested and owned homemade, built in, and removeable batteries for over 25 years. Way more than 25 lights. Built in is much less work, gives a little more performance, and usually longer run time.
I ride with a spare headlight, and a spare tailight. Plus small lights to fix a flat in the dark 50 miles from home. Li ion batteries run longer in the cold than other types of batteries.
For 15 or 20 years lots of 120 to 150 mile rides. Coming home at midnight or later often. My newest lights are all universal strap mounts, they rotate to 15 bikes. Some or the strap lights are over 10 years old, only one strap failure, it was 100f in the garage and I pulled too hard on the strap. One of my trikes is ridden with three tail lights, and three headlights. I have a power strip with lots of chargers on it. Need to charge my camera, my phone, and my lights all at once. It's easy. Almost forgot, a helmet light and a backup helmet light.

The last four pictures in this album shows lights I used yesterday. Some of them are over ten years old.

Nosmo Trike 30 m. EBBP 11-2-22 | Flickr

USB rechargeables. They run brighter, longer, and are far more economical over time.

Prices have skyrocketed on good quality alkaline and NiMH D, AA, and AAA batteries. I have a few devices that still use them, but I doubt I'll buy any more. Batteries from the dollar stores are usually a bad value because they're inferior quality and don't last long. Over time you'll spend as much as you would buying a good USB rechargeable light to begin with. Pretty much the only devices I still use fairly often that take AA and D batteries are my old shortwave portable radios, and a couple of them have always been pretty thrifty to run for many hours per set of batteries.

I've had good luck with Nite Riders headlights, and if I'm recalling correctly those can be disassembled to replace the batteries. Light & Motion headlights have been pretty good while they last, but the batteries are good for only a year or two before the runtime per charge declines and the barrels are not made to be disassembled. The only reason I'll keep my L&M Rando 500 awhile is because it can be charged and run simultaneously from an external USB battery via their proprietary cord -- albeit only on low or pulsing.

Cygolite Hotshot and Hotrod taillights seem to last a long time. Ditto the Blackburn 2'Fer, one of the first all purpose lights I bought back in 2015 or 2016 when I resumed cycling after a long hiatus. I've used that 2'Fer, mostly on my helmet, on almost every ride for years. It still lasts pretty much the same runtime per charge. If other Blackburn lights are as reliable, I'd consider them as well.

If I was serious about bicycle commuting I'd get some kind of dyno setup for head, tail and side lights. But even those glow-winky wheel lights that enhance visibility can be run pretty economically from batteries. Those wheel lights don't need to be bright because the motion enhances visibility.

I use a mix of both in my 1 hour maximum commute context.

The USB devices are generally brighter, which must be due to the higher voltage battery (over 5V versus about 3V for two rechargeables). However all of them turn off abruptly when discharged whereas the rechargeable AA and AAA lights just get dimmer. I like having at least one rear light that will give some level of glow…so I don’t go completely ninja.

Though not a rear light, my all time favorite bike light is the discontinued Philips Safelite. It is USB charged but the 4 in-series batteries are standard AA form. I’ve replaced the batteries on mine twice. The aluminum case is a Sherman tank.

I have not bought disposable AA or AAA batteries for over a decade, but I recall being at work with low batteries for my taillight, I accidently left them on. There was a Walgreens a block away, bought some AAA batteries for my light for the ride home. You can't do that with internal battery.

I use two different Planet Bike Superflash taillights, both take a pair of AAA batteries. For straight roads, the plain Superflash, it has a tightly focused beam that when carefully aimed straight back is very bright to following traffic. But if I will be on a winding road with some ups and downs, the Superflash 65 has a much wider beam so vehicles will see a bright flash if they are not straight behind.

I use both for bike touring, typically one at a time depending on road conditions, but if overcast or foggy will run both on flash mode.

I charge up the batteries once a week, even if they are still bright because I want them to stay bright.

The batteries that I prefer are no longer sold but Eneloops are a very good battery that I would recommend.

Make sure you get a smart charger that knows how to charge them up to full and then quit charging, the cheaper chargers (dumb chargers) just charge at a slow rate and keep charging in perpetuity, avoid those.

The charger I use at home is made by Accupower. For touring the charger I use is no longer sold, for touring I want a AAA/AA charger that operates on USB power so my dynohub powered USB charger can charge them.

For bike touring, the GPS, taillight flashers and headlamp for my head all use AA or AAA batteries so that I can swap batteries if batteries in a device are low so I can keep using it.

I switched to rechargeable taillights a while back. OTOH, they are backups, I have dyno taillights on all my bikes. I also carry spare lights on long rides.

My bikes stay in an un-electrified shed. The bike blinkies use batteries. The helmet lights and removable main headlight (and shoe lights in winter) come inside with me so they are rechargable USB.

The problem with AAA battery powered tail lights is the lumen ratings are very low, at about 50 lumens; whereas with a non-replaceable lithium battery tail light you can get upwards of 300 lumens. My taillights have rubber straps which make it easy to take them off, bring them in, and charge them, just like I do with my headlights. My best taillight is the Nite Rider Omega 300, the newer model is called the Omega 330, the numbers represent the lumens, this light has a variety of modes, and needless to say it's extremely bright in the brightest settings. But you are correct about the LED's lasting longer than the non-replaceable battery will last, which I think is insane that we can't replace those batteries when they'll no longer take a charge. 99% of all headlights use non-replaceable batteries as well, crazy, just crazy.

Planet Bike Superflash that costs around $25 uses a AAA battery, it's not very bright, but it does work; it's a old design that has been around for a long time because people, like you, want a taillight that runs off of standard batteries. There might be a couple of other AAA lights but I could not locate one in a brief search.

FWIW, you'll need to experiment with NiMH AA or AAA rechargeables in your devices. Some do very well with the slightly lower voltage in NiMH, while other devices need the full 1.5v per cell to operate as expected.

I started using NiMH about 20 years ago after switching primarily to digital for my "serious" photography with my first Nikon dSLR and SB-800 flash and peripherals. The SB-800 performed perfectly with NiMH rechargeables, as did my compact P&S digital cameras.

But other devices with constant drain -- pre-LED flashlights, portable radios -- tended to poop out quickly with NiMH AA and AAA batteries. It's possible that newer constant drain devices like flashlights and radios may be efficient with NiMH batteries. All of my shortwave portable radios are from the 1970s-90s, but some of the newer generation DSP shortwaves may run just fine with NiMH rechargeables.

I've also tried lithium AA and AAA batteries in bicycle lights for winter use, but the expensive lithium cells didn't last long, although they did seem to work well in cold weather. But we don't get enough seriously cold weather to make it worth the expense.

Rechargeable batteries is my choice purely based on the possibility to get the replacement anywhere if you suddenly forget to charge lights. I use AA, AAA and 16500 powered devices.

If you want to use a light with AA batteries I suggest getting a 4 pack of Ikea Ladda 1.2V 2450 mah batteries that are made in Japan, not China, that only cost $9 for the 4 pack. They also have them in the AAA size as well. These batteries are actually better, by a wide margin, over the Eneloop's, I have both brands, the Eneloop is not lasting as long in the number of charges that it can take vs the Ladda before they error out on the charger; the Ladda keeps my headlight burning longer by about 20 to 30 minutes per charge. As my Eneloop's begin to fail I'm replacing them with the Ladda's, and the Ladda's are a lot cheaper than the Eneloop's.

Buy those Ladda batteries on the Ikea site, they cost more on Amazon!

I agree on the AA batteries. The 2450 mah used to be white, now gray color. They are the ones to get.

But they no longer sell the 900 mah AAA batteries, or at least not in USA. Now they only sell 750 mah AAA. I am not saying the 750 mah batteries are bad, but they do not have the high rating that the ones I previously bought have.
https://www.ikea.com/us/en/cat/batte...hargers-41070/

Photo below, the battery charger that I bring on bike touring trips, loaded up with my 900 mah AAA batteries from my two taillights. I charge them once a week on tour whether they need it or not.



Next photo, the one green light tells me that one cell was not yet fully charged.



And now that I do a google search for the charger I use (Powertraveller Powerchimp), nobody has it in stock, so it might be out of production.

Would enough extra batteries weigh less than that charger?

I take one of these on trips. Will charge Li-ion too.
https://www.ebay.com/itm/163404257704

Can't find it currently available but nitecore do have a similar product...
https://www.nitecorestore.com/Niteco...-nite-lc10.htm

If you are asking about my Powerchimp, that is 75 grams without cables, or roughly 3 oz. I am not going to get excited about 3 oz.

Plus, when camping the headlight (for my head, not bike) also uses NiMH batteries. And my GPS takes NiMH batteries when touring.

Yeah, I carry a set of extra AAA bats for a Nebo Slim flashlight I use at the campsite because, like you said, carrying a charger weighs more and takes up more space, plus a charger uses 110 volt American plug, I can't plug that into my solar charger I take to charge my phone, my small bike lights, but when I'm bike camping I don't take my AA powered Philips Saferide, I don't need it since I don't travel in the dark when bike camping. Plus most campsite stores carry AAA bats, and if not I can always find a store that will, so the extra set gives me a huge cushion of time to buy another set after the first set dies.

The USB rechargeable lights are much more convenient to charge, and as others point out, they work much better. I'm not happy that I usually have to replace the entire light when the battery dies, but this is a price for so-called progress.

I have a fantasy of installing an electrical system on my bike, powered by an external 5V lithium-ion battery, but it will take some work. I could power rechargeable lights, including those whose internal batteries have failed. I could also power *some* models of lights intended for dynamo use. If I ever succeed, I'll post here. My spouse has a habit of carrying one of those batteries when she goes out, and she charges her phone with it. She could extend that habit to the bike. She cannot, however, remember to keep her bike lights charged, so this would be an improvement for her.

My NiMH battery charger (the one in the photo that is no longer sold) draws USB power. And there have been other smart chargers that draw USB power. I charge up a powerbank with my dynohub, then later use that to charge up my AAA batteries, AA batteries, camera batteries, phone battery, etc.

I used to use a Sinewave Revolution to convert dynohub power to USB power, but a few months ago I bought a Version 3 Cycle2Charge that puts out roughly 50 percent more power than the Sinewave, that will be my new go-to dyno powered USB power source for touring.

I think it comes down to personal preference, I would rather keep using the taillights I bought a decade or more ago, and since they use NiMH AAA batteries, I can. The GPS I use for backpacking, canoeing, kayaking, that takes AA batteries, have been using it for nine years. The GPS I use on my bike, that also takes AA batteries.

And if one of my devices needs to be recharged, I can change the batteries and it is immediately recharged, do not have to wait for an internal battery to charge.

I needed to replace a headlamp (for my head, not bike) last summer, bought one that takes a single AA NiMH battery, it works great.

I am not trying to convince you to change, I am just pointing out that there are different opinions.

That's fine and fair, [MENTION=203914]Tourist in MSN[/MENTION]. We all have our reasons and motivations.