gauvins

Context: Several sensors require cr2032 cells (cadence, speed, temperature, HRM, etc.) so I wondered about the possibility of relying on rechargeable cells (LIR/ML).
Experiment 1: recharging. Failure. I've purchased several lots of ML/LIR cells and chargers. Mostly fails with ML, and very unreliable results with LIR. Not worth the trouble.

Context: May as well use low power CR2032 see-me taillights. Very cheap and surprisingly efficient. Benefit over rechargeable USB is that you can swap in fresh batteries if the light goes dead in the middle of the night.
Experiment 2: Decathlon sells small ("turtle") taillights nominally rated at 44 hours in blinking mode. I've set two on my desk, one fitted with the provided no-name coin cells, and another with Pro-Cell batteries, rated at 745mWh, vs what I assume to be 650mWh for run of the mill 2032. The no name powered taillight blinked for 5 days (120h) whereas the ProCell lasted more than a week (170 hours). I'm impressed.

Takeaways: Rechargeable 2032s are unreliable. ProCell batteries do work (much) longer in this use case. I've retired my old taillight and will carry a pair of turtles on my back. I conservatively plan on an average of 8h/week with taillights on. Looks like a pair of CR2032s would get me going for close to 6 months...

Tourist in MSN

That is a lot of hours for a very small battery. Have you looked at how bright it is when you are a 100 meters away in daylight? That was what I did with my taillights before I decided if I wanted to rely on them.

I was surprised by your capacity rating so I checked, the sheet you linked to lists capacity as 260 mah. The 745 number is milli watt hour.

Energizer lists their 2032 battery at 235 mah, which is only slightly less than the Procell you cite.
https://data.energizer.com/pdfs/cr2032.pdf

I usually run a pair of Ikea low dischage AAA batteries in my Planet Bike Superflash taillights, they are rated at 700 or 900 mah (older ones were 900). I usually recharge them once a week whether they need it or not when on a bike tour, I want them to stay bright. If I needed to replace with disposables, AAA are easily obtainable.

Thanks for the analysis, I will not bother checking out rechargeable 2032 batteries. I go through a lot of those batteries each year and considered checking the rechargeables. I had to replace a 2032 in two devices in the past month, I usually buy 20 about at a time.

gauvins

Tourist in MSN Thanks for noticing my mistake (Wh vz Ah) WRT to Energizer, I find 653 mWh, i.e. 15% less energy.

No formal test. Looks bright enough. I never felt the need to use blinking lights during daytime.

ARider2

Can you comment on whether the Decathelon light is suitable in a rainy environment, is it water resistant or water proof?

gauvins

I've used them years ago, both as tail and headlights. Withstood crappy weather. The black rubber envelope semi-loosely wraps around the electronics -- I wouldn't use these as diving lights (perhaps use some weak glue to seal the envelope?)

Perhaps purchase a few and test in the shower, and then bath. I'll read your report with considerable interest

veganbikes

It sounds like a light that would be best suited for a kids bike who isn't going to really be riding at night but wants to be more like their parents. I have sold similar lights marketed directly for kids and also gotten some in give away situations like branded corporate stuff. Would not want to trust it for actually keeping me seen especially not in inclement weather. 2 lumens is not much and 2 lumens in even less visible conditions seems even worse.

I understand that these lights are generally low initial cost and small and unobtrusive and all of that but I want to be seen easily without struggle and am willing to spend a tiny bit more to get that.

gauvins

veganbikes interesting. OTOH, research has shown that biomotion increases the probability of early detection (Edewaard 2017. The Conspicuity Benefits of Dynamic and Static Bicycle Taillights at Night). The authors write that heel-mounted lights were detected at a distance 5.5 greater than equivalent non-blinking seatpost lights.

Tiny turtle lights can probably easily be heel/pedal mounted.

That's the next frontier in kit optimization

ARider2

Everyone has different needs and I already have inexpensive lights similar to these which I keep on the bike all the time but one good rainstorm can kill them if I don’t dry them out. I rarely use them except for the rare occasion that I am out at night maybe once or twice a year.

Tourist in MSN

I have put reflective tape on the crank arms on most of my bikes. Initially had enough tape for only a few crank arms, but a few months ago bought more tape and now have it on front and rear of both crank arms on most of my bikes. Pedal reflectors would be better, but SPD type pedals are not designed with that in mind.

I have no clue if it helps at all during daytime on an overcast day, but most newer cars have headlights or other front bright lights on during daytime so maybe it will help a bit?

After decades of commuting on a motorcycle, I am convinced that on a sunny day, visibility is not a problem, but on an overcast day a motorcyclist or bicyclist should behave as if they are invisible to all car drivers. If you can't see your shadow, that is an overcast day when you need to be most careful.

Half a century ago, leg lights were popular for bicyclists at night, a two C cell light you strapped on your left leg, front side had a clear lens, aft side lens was red.

gauvins

Clever
(thanks for the vignette)

Searched Amazon. Several options, nothing outstanding yet, though. One is a cylinder 1.5x.25 inch, fitted onto a strap, claiming 500hrs on a pair of CR2032; another is a rechargeable slap band claiming something like 8hrs on 1hr charging time. Neither looking durable, though. Will try to find about alternatives and eventually post.

Tourist in MSN

The old leg lights, I did a google search and found this writeup on them.
https://midlifecycling.blogspot.com/...er%20light?m=0

Mine cracked from screwing it on too tight, wrapped tape around it which kept the crack from getting worse. I am pretty sure it went into the trash years ago.

They were not bright enough to see where you were going, but they were visible to most car drivers. I think city street lights were much dimmer half a century ago and there were fewer of them.

And since the leg lights were attached to you and not the bike, theft was not a concern. They pre-dated helmets, so for many people (including me) they were their only bicycling safety device.

veganbikes

I could agree bio motion will help but I think a super duper low lumen light is not going to be easily seen wherever it is. While the light could be easily mounted visibility is the key.

Be bright be visible out there.

ARider2

Your post jogged my memory and I remember having one of these sometime in the late 70’s. It was made of white plastic and a bit heavy with two C cells. I’m pretty sure mine is long gone in the trash.

gauvins

Totally agree. Perhaps worthy of a distinct thread. My post was only to report on a rather silly test.

One thing -- reflective clothing is perhaps the first and best line of defence. I remember being fascinated by the hi-viz gear used by ferry crews, in Scotland I believe. Looking into the hold from the onshore pre-boarding area was like watching a sci-fi movie with aliens moving around inside a cavern. Simple 4-inch wide reflective arm, chest and leg bands. No annoying blinking. Striking. Deceptively simple (white) -- at close range you would not notice these bands.

stevepusser

I have some bargain sources of good hexcell reflective tape, so it's all over my bikes and their wheels, my helmet, gloves, heels, bags, and so on. Also rec'd a very bright white full reflective jacket on sale at $17 on Aliexpress last week--am quite impressed by the quality, so that I ordered the amazing technicolor dreamcoat version at the same sale price yesterday: https://www.aliexpress.us/item/3256805929998995.html

veganbikes

Fair dinkum.

Clothing would not be the first line of defense. Anything that is not directly providing light is less visible without someone else's light. That is not to say it is a bad thing and totally without merit obviously it does make it easier to see someone when light is shone. In a situation like you are describing they are invaluable but it is a safer environment with regards to reflectivity as people are looking for it and know there are people working and it is active site. On the road people aren't really looking for cyclists or really anyone sometimes they aren't expected there are usually higher speeds of vehicles (not always and some job sites and loading docks can have fast moving vehicles and they aren't truly safe).

I should note that I just got a ProViz Reflect 360 cycling jacket and I do love the visibility when light hits it it really shows up though the inside of the jacket that mesh I am not a fan of and the jacket is a bit heavy but overall great purchase but I wouldn't trade it for decent lights but is a great addition and certainly one I am so far glad I made. Being more visible is important and having your own methods for making yourself seen is the key having ridden and seen plenty of cars at night who don't use headlights for whatever reason having to rely on them to make me seen is not a good thing. I love pancakes of all forms except human ones made from me ; )

stevepusser

Well, yes, why not both, as they say? Don't get me started on my front and rear light collection, as well as those built into my ebike. Currently building up a collection of a few Anduril 2 firmware based lights with cool sets of strobe or stuttering bike modes--brightness can ramp smoothly from one lumen for off bike use up to 3500 true lumen. (until the auto temp control ramps it down, that is)

Tourist in MSN

I used to commute on a motorcycle with a H4 halogen bulb, roughly 1100 to 1500 lumens at highway speeds. It would have been nice to have double that amount of light like the cars had with their two headlamps, but it was doable and safe.

When you are going bicycle speed, I do not understand why you need a strobe light that is 3500 lumens.

A few months ago I was riding my bike over a bridge on a bike trail, bridge was about 8 feet wide. Daytime but overcast so I did not have dark sunglasses on. And suddenly some E bike rider is crossing the bridge towards me with a super bright strobe light. I almost crashed into the wire fence on the side of the bridge because that strobe was so blinding.

stevepusser

Well, no, the 3500 lumen is only for a short time in Turbo mode before the light automatically ramps down the brightness. The bike mode is a steady light with either stepped or stepless brightness adjustment that "stutters" a little brighter once a second to hopefully get drivers' attention. I also ramp down the brightness at red lights so I don't accidentally shine it into cars alongside and to save battery. During daylight, I put the light into "party strobe" mode slowed down to 2 Hz so it's a nice daytime blinky running light.

That's with the advanced Anduril 2 settings. You can also just ignore all that jazz and use the lights as on-off rechargeable flashlights. Check out Youtube for Sofirn and Wurkkos light reviews, though most of those don't have Anduril. For day rides, I use a very small Sofirn sc21 pro (1000 lumen max) which weighs a few ounces, and I've used for about an hour as a good headlight when the rides last into the evening. I now also carry a couple of extra spare batteries for it (rechargeable cr123) "just in case". The bigger and brighter Anduril lights are for my class 3 ebike bars or longer pedal bike night rides.

Hey, this is 2024! I just got a mini battery bike pump (a Toptrek Airgo) that is about the size and weight of a bar of soap, and can pump up a mtn bike tire about four times before it needs recharging, which could be done on the road from the aforementioned 3500 lumen (max turbo) Wurkkos TS21 light, which can act as a battery bank. (My other light between those two is a 1700 lumen max Sofirn SC31T.) On my first ride a few days ago with that pump, I got a large hole in my rear tube that the the sealant couldn't handle about 3 km from home, and am able to confirm that it does work well, at least for one 50 psi 1.5 inch road 26in tire refill.