Luxos U never shuts off?
 

I've only started noticing this in past couple of months, but my Luxos U never goes completely dark, not even when I turn it off. Has anyone else seen this? It's not the stand-light function because it's much dimmer than the stand light. And it lasts forever. The longest my bike ever sits without moving is two days, but even then there's the dim glow from the headlight. It seems to be functioning as normal when I actually turn it on, so I'm not too worried, yet, but it's a little weird, and I hope it's not a precursor to problems down the road.

Had a very similar problem on a Cygolite Expilion headlight; extremely difficult to see during the day except in a windowless interior room and barely visible outside at night. Cygolite fixed it for $13 (including return shipping) by replacing the circuit board.

A couple of days ago I noticed that the two LEDs on my my Luxos U were dimly lit. The bike had not been ridden for a few days. When I spin the wheel the light functions normally. I have the early version on the Luxos U, the USB port is built-in the handlebar switch housing. I purchased this product 2 1/2 years ago, to date, no problems at all. I suspect a failed transistor (IC, of course) is allowing current to leak into the LEDs. I don’t think this is serious and there’s really nothing that can be done about this other than parts or complete unit replacement. My plan is to use the product until failure.

Given that mine is out of warranty, that is my plan as well. But if/when it does completely fail, I think my plan will be to avoid combined devices in the future. The light with the built in USB charger was slightly cheaper than a good dynamo light and a separate USB charger, but now if I have to replace one, I have to replace both, so it may not be cheaper in the long run.

I have some dynohub powered lights (old Lumotec Ovals, now out of production), one USB charger (Sinewave Revolution) and two lights that also have the USB charger built in (Luxos U and AXA Luxx 70 Plus).

Of all of those, the Luxos U is my favorite in part because it has the pass through cache battery. But if my Luxos U stopped working soon after the warranty expires, considering how much it costs I would be pretty angry. Something that expensive should not be treated like an expendable item.

If you are lucky, only part of your Luxos U would stop functioning. For example if the USB portion failed and the light still worked you could wire in a USB charger in a parallel circuit while continuing to use the light.

I find that even with the cache battery, I don't always pull sufficient power to keep my phone charged up, largely because I'm slow, and every time I drop below a certain speed, the phone stops registering a charge, at which point the screen comes on. Then I speed up, and start supplying a charge, at which point the screen comes on. So depending on terrain and what speed I maintain, plugging the phone in may cause it to run down faster with all the screen activity. As a result, I just charge a battery, and use that to charge my phone, so I probably would not miss the cache battery if I had to do without it.

Yeah, this is my 2nd one, too. It was already replaced under warranty once. I really like the light, and I really like the charging ability, so I'll keep it as long as possible, but if this weird, light-bleed issue is a sign of future problems, I will not be replacing it with something else. Of course if the light continues to work, I'll be happy to keep that in service for a while, but if the light fails, I'm not likely to want to keep an extra light on my bike, just so I can have a charger.

The other disadvantage of this set up is that I have occasionally had, and would like to have again, multiple bikes with generator hubs. Ideally all the bikes would have their own lights, but it'd be good if the charger were easily swapped between bikes. I wouldn't want to move my Luxos U between bikes "just in case." I'd only do it if I knew I was going to be using it on the other bike.

I find that happens on occasion too. I believe that what is happening is that the device that I am charging is pulling power out of the cache battery faster than the hub can replenish it. So, when this happens I just stop charging whatever I am charging or a while, say maybe a half hour to give it some time to replenish the cache battery and then start charging things again. I use it for bike touring, so I am trying to be self sufficient without having to plug into an outlet.


I have been accumulating lights/chargers at the same rate that I have been accumulating wheels with dynohubs.

But I have five different forks that I will put a dynohub wheel on, so I have zip tied wires with a Shimano type connector on each of five forks. (SP and Shimano dynohubs use the same connector.) And then I have some quick connect type connectors at the fork crown, so I can easily plug and unplug things. This way I can move a dynohyub from one fork to another fork on a different bike.

I also do not use wired taillights, all my taillights are battery powered. That greatly simplifies my wiring.

First photo, the quick connectors between the yellow wires and black wires make it easy to switch components at that point.

Second photo, the wires at the other end of the fork (on a different bike) plugged into an SP hub. If this second photo looks confusing, I have a Tubus Tara low rider front rack bolted to the fork, plus fenders, and a bolt on type skewer instead of quick release.

Update: My bike continued happily with its weird, never-quite-off light until this weekend. On Friday I tried, for the first time in probably 5 or 6 months, to charge first my phone, and then a cache battery using my Luxos U. The phone didn't seem to be charging properly with the inconsistent power output, so I switched to the more forgiving battery. Batter blinked it's charging sequence for a while. The Luxos U switch showed red (for cache batter full, I think) for a while, then the red light went to blinking, and then it went off. And nothing has worked since then. The light continued to have that slight, never-quite-off glow until at least Sunday night. I haven't checked since then. The red, cache light battery never returned on a 40+ mile ride home on Monday, and the headlight has ceased to function. Changed front wheels to make sure the generator hub was not at fault, but, no, it's the light. It's not passing power through to the tail light, either. I think the tail light has protection against over-volting, so I can wire my tail light directly to it while looking for a new headlight and continue to get some use out of the set-up. Or maybe if I bypass the switch, I can get the headlight working again? Not sure, but going forward I won't try another headlight/USB combo solution. It leaves me with two things to replace at once when it fails.

finally bright enough for the senso mode to realize its not dusk on overcast days?

My simpler Eyc Senso has no problems there.. in rainy days ..

I recall reading on a different thread that someone described the cache battery failing and they had the skills and knowledge to replace it. I just found it again:
https://www.bikeforums.net/18938859-post19.html

That is the kind of thing I would try if it was mine.

I have a total of three USB chargers, two combined with a headlamp and one separate charger. For bike touring where I would typically be relying on the USB charger for several hours each day, I bring my Sinewave Revolution, a pass through cache battery to use with it, two battery powered taillights and a low quality dyno powered headlamp.

Part of my theory when bike touring is that I will be using the USB charger during part of every day, I might want to have a flashing taillight on while doing that - thus the battery powered taillight(s), and the reason for a low quality headlamp is that I almost never am riding my bike in the dark while on a bike tour but I might need a light for a tunnel. In other words, the light is one that I am not relying on very much, so I bring one that if it gets damaged I won't get too concerned. I think the Sinewave Revolution is one of the best waterproofed chargers there is, the electronics are encased in epoxy. That is why it is my go-to charger for bike touring where I will be relying heavily on a charger.

Same problem here.. The two LEDs never shut off at my Luxos U. Otherwise, everything is working fine, including charging, but still it sucks, as I have to cover the LEDs at night when wildcamping and it costs some valueable charging power.

Anybody got to a solution? Will contact my retailer..