I have two Cygolite Ranger 1400 headlights. Each has been sent back to the mothership for repairs - both plugs for the mini-USB came loose. But now the issue is batteries. For a while, they both worked great. Then one would just die in under 15 min. I finally labeled them with a silver Sharpie - #1 and #2 . #1 seemed to be culprit. It is the older of the two, so. But even labeled, I wasn't sure; I kept second guessing my memory, "wait... did #2 die last time?". A proper test was in order.

Yesterday, I fully charged both lights. The green light goes from flashing to steady green when it's charged. I set the stopwatch and turned them both on High.
- #1 died in 4 minutes and 20 seconds
- #2 died in 2 hours (yes, hours) and 30 seconds

I thought "Okay, good. I have one dead light and one good light." I tossed #1 in the bin and charged up #2 for this morning's ride.

This morning (at 5:45am), after charging #2 all night, it died in 9 min... just long enough for me to get to the darkest stretch of road. Of course.

So. What have I learned? Nothing. Well, I did learn that I can't trust either light and already ordered a new light. But, what can I learn here? Did running #2 all the way down ruin the battery? Neither light is new - #2 is just newER than #1.

Side note, but a big one: I was VERY careful to keep track of which light died when, etc. #1 died in the "test." #2 made it 2 hours in the test... and died in 9 min. this morning.

Maybe you need to try another brand and see if you have the same experience with them. For many years I've seen more than a few people post that seem to have issues with every thing they buy of one brand, but for some reason apparently get good results with a similar product of another brand. And both brands are equally favored and give excellent service and life to the overwhelming majority.

I've always had good luck with most anything that has a built in battery. It's the devices with replaceable batteries that I have more issues with. Particularly coin batteries.

I've got a pair of Bontrager ION's that are over 6 years old. They still charge up and hold a charge. They don't put out the light your

Interesting problem!
It might be worthwhile to repeat the test a couple of times. If the lights have been in storage, sometimes a battery might not have full capacity right away (at least this was true for earlier battery chemistries... not sure about lithium).

Regarding discharging the battery all of the way... it's generally not good for the battery. Of course, a good light will shut off before discharging the battery far enough to hurt the battery lifetime.

Any idea how old the lights are? In addition to having a finite number of full charge-discharge cycles, many battery chemistries have a lifetime that is independent of how little they are used. The manufacturer should be able to provide some sort of number on this.

Steve in Peoria
(I think I managed to avoid answering any questions. sorry)

Yes, unfortunately, you may have discharged the battery to the point where it will no longer take a charge anymore - hence the 9 minute life.
litime.com/blogs/blogs/is-it-bad-to-fully-discharge-a-lithium-ion-battery#:~:text=It is generally not recommended,and reduce its overall lifespan.

Some Lithium Ion batteries or devices have a protection circuit so that if the battery is discharged too low, it is prevented from charging. That is a safety feature, as discharging a battery too low and then charging can cause it to become a fire hazard.

I use taillights that take AAA batteries, I use rechargeable NiMH AAA batteries. I have lights that are 10 years old that still work great, although the NiMH batteries that I used a decade ago have been recycled. That said, good AA or AAA powered headlamps are quite rare. I got a B&M one to carry as a backup on brevets, I do not recall the model name and it is not super bright.

That's some good info (especially that linked article Bald Paul ) Thanks guys!

It seems my lights are just the product of lots of use and minimal (realistic?) care. The lights do have that protective feature - shutting off before they're totally drained. But, when out in the dark and the light just turns off... yeah, I have forced it try harder by turning it on several times. That does work - the lights come back on for brief periods. I've even planed that use, i.e. "I'm safe here, but will need the light for that intersection... and ON!"

So, I'm sure I've beaten up the batteries doing that. I'm also guilty of storing the lights in the garage - temps range from 30-110 degrees. Oh, and I do not recharge to 50% for optimal non-use storage.

So, what I've learned is that:
A. Both lights are shot.
B. They may have lasted longer if I managed/cared for them better.
C. I probably won't
D. I'll have to buy a new light a bit more often
E. I think I'm okay with D

Battery life isn't forever on these devices. After so many charges the batteries just won't take a charge anymore,

I've had this happen with cell phones and bike light batteries.

I don't generally ride at night, so I use front facing headlights "to be seen", rather than to see at night. For over ten years, I've used Knog headlights, the "Blinder" line of products, and have been very satisfied with the battery life. I'm not sure what type of battery they use, but the one that is ten years old still performs very well, almost as long as the newest, one year old model. They each have a red low battery indicator light that gets my attention. I generally don't run it very long after it comes on, which is why I have two of them to use on longer rides. I use the flashing mode, but you can use both of the double Cree LEDs at once if you're going through a tunnel or are on a dark road.

I'll put a plug in here for the Fenix lights that use easily-removable 18650 or 21700 Li-Ion batteries.

I suggest/recommend NiteRider lights...been using them for decades, literally, and they are fantastic and last years.

Were you using the same charger for both lights, or cable? Maybe that's what is bad, not the lights themselves. I've put my iPhone on a cable overnight more than once only to find only a 5-10% charge because the cable was bad and it only got a short charge before it got moved. Worth looking at if you haven't already.

I went back to AA/AAA battery powered lights, the batteries last me about 60 days or longer.
I keep a few extra batteries on board if needed and no longer have to worry about charging.

Cateye still makes a few.

I love my Cateye TL-LD630 tail lights!
They just use one AA cell and last me for weeks per charge (based on how I use them).
Cateye's page: https://www.cateye.com/intl/products...ts/TL-LD630-R/
I don't think they've been produced for a number of years, unfortunately.

I really appreciate that Cateye sells all of the various mounting brackets and bits through their website. This lets me just buy a couple of lights and a bunch of mounting brackets, and be able to use the lights on any of my bikes.

Steve in Peoria