[Closed] Dynamo light with usb charging function

I've had a B&M Luxos U (which is what I think you mean) for a few years. It worked well until recently but I think the cache battery is fading now, leading to inconstant charging which I'm hoping to get replaced.

Other than that its always worked well, putting about half a charge in my phone during aways slow touring. The light is very aged to, a nice wide dipped beam, great on the road. I ran the wire from the dynamo to the fork crown up inside the fork leg through holes already there. It was a pig to get in but neat once done. I protected the ends of the cable where it exits with heat shrink tubing to stop the wire chafing. From the light to the bars the wire stays external as there's a high/low beam with on the bars that the USB connecter connects to.

AXA used to make something similar but it didn't have a cache battery so wouldn't provide a smooth stable current like the B&M

That Sinewave is ridiculous money. You could get 3x B&Ms for that price to do the same job.

EDIT, actually nearer 4 B&Ms at the current prices....

I had a Luxos U. It failed after not much use so I got a USB ewerk instead. Chum had a U as well, his failed and he got another. It's still going strong after a couple of years of very occasional use.

Make of that what you will...

The Luxos U is a good light and does what it's supposed to very well, although it's not sealed properly and my original two both died after getting wet. I have a replacement now (warranty) which I'll waterproof somehow before taking out in the rain.

Unfortunately I'd not recommend it,  because of the lack of waterproofing.

I think the original versions of the Luxos U had problems with water getting into the switch/USB connection. But apparently this has been improved with later versions.

Probably worth putting the USB connection in a handlebar bag or top tube bag, to help keep it dry.

Maybe consider a separate light and USB (e.g. Cycle2Charge, etc.) - more flexibility buying the two separately . They can just be wired into the same plug by twisting the cable ends together.

My Luxos U was one of the later versions, my chums the earlier one and his drowned. Mine committed suicide some other way and just stopped charging from the USB port.

I used a B+M USB Werk running up through the fork leg and o-ringed to the downtube.  That way I wasn't restricted only to lights that offered charging.  Since I can't now ride so far as intended I just use a large power bank for both front light and charging duties.

*Stealth ad - my USB Werk happens to be in the classifieds 😎

Cycle2Charge

I wouldn't. Utter cross.

Ewerxs seems to be the longest lasting by all accounts.

I've had a Luxos U for some time (in fact I think I ordered one almost as soon as it was announced). Haven't had any trouble with mine even in the wet, but there certainly seem to be a number of reports of the original one (like mine) failing. B&M revised it by hard-wiring the extension lead and I've seen few if any reports of water-related failures of those.

That said, I've never found the USB charging feature entirely satisfactory. It works well enough if you use it to charge a battery (whether that's the internal cell or an external one) but if you're charging devices you're still going to get intermittent charging: with the lights on, you have to be above a reasonably high speed to get enough additional power to charge; and with the lights off, you're fine until you've exhausted the internal cell and then you'll find power dropping on climbs again.

There are a couple of other lights with USB charging functionality (Axa make one, I think, maybe Herrmans) or there are external devices like the E-Werk and The Plug.

To be honest I've ended up concluding that unless I'm going multiple days without access to mains power overnight (which basically doesn't happen) it's easier and more reliable to simply use an external battery.

That said, if you've got an external battery and a Luxos or similar, then you kind of have all the bases covered.

https://twitter.com/mashing53/status/1042148090344624128

The cycle 2 charge is good, I've had two (the first got stolen along with the bike it was mounted on) and not had any issues. I think some have had problems using them off road, maybe the vibrations damage the internals, but 5000km+ of road riding and mine is still going strong. You should switch it off/unplug if you're not charging anything though.

I tried a Luxos U and reached a similar conclusition to Bez. Unless you really are in the middle of nowhere for an extended period you are probably better off with a battery pack and mains charger. USB chargers are a lot faster than they used to be too (around 20 watts i think?), so even a 30 minutes stop in a cafe can recharge a phone by 80% or something, whereas it would take hours of riding to do the same on a bike as you're only getting 3w ish.