DIY masochist

I'm in the market for a new light, and it seems like most of the nice ones these days are USB rechargeable. My current light takes AAs. I like the fact that I can keep some spare batteries in the seat bag or stop at a convenience store and pick some up when I'm out and about at night and it dies. I will definitely be in that situation again at some point. I have a small USB backup battery for charging cell phones, so I thought maybe I could use it to run a USB light off of until I got home to give it a proper charge? Has anyone tried this?

znomit

Some lights will run while they charge, some won't.

DIY masochist

I have a NiteRider Mako 200 lumen light right now that is mostly enough, although sometimes not quite strong enough for riding on really dark unlit trails / streets. Those Cygolites look interesting. I wonder if it's possible to rig up some kind of external battery charger so I could charge the cartridges by themselves and swap them out every once in a while. I also wonder how long the cartridges hold a charge, because I know rechargeable AA batteries will not stay charged for very long at all if they are left sitting. Or maybe that's just a NIMH thing? I just checked Amazon and apparently they now make lithium ion rechargeable AA batteries with a built in USB head (!!!) Maybe I'll have to try those. I'm all about reducing battery waste, but I haven't been able to because the rechargeables I kept in my seat bag just died while they sat in there.

I checked and all the generic 18650 battery lights on Amazon look kinda sketchy quality to me...

DIY masochist

& a dynamo hub is an interesting idea, although I guess I'd have to have a wheel built for that. Considering the Surly is my pampered baby and my main ride, it's not out of the question for me to get a wheel built. It certainly would come in handy for touring.

Tourist in MSN

The low discharge NiMH batteries keep a charge a long time. Two brands are pretty common, Eneloops (I have used the regular Eneloops for years) and also Ikea Ladda batteries. Ikea sells two versions of NiMH, the Ladda ones are the better ones.

The last batch of Ladda batteries I got are fantastic. I am charging up a pair of Ladda batteries for my GPS in the photo while on a kayak trip.

1nterceptor

Here's my short comparison of a dyno powered light(Edelux II) vs. a USB charged light(Planetbike Touch800).
You'll have to decide if the convenience of a dyno is more important than total brightness:
PS, there are also lights that are made to run off a power pack. I'm not recommending this light,
don't have personal experience with any. Just using it as an example:
https://www.amazon.com/OVERMAL-6000L...bicycle+lights

noglider 

Most people who try dynamo lights kick themselves for not getting them sooner. I'm one of them. I love not thinking about charging. I don't even switch the headlight off. I just ride. B&M headlights have shaped beams which ensure you're not blinding anyone, and they make good efficient use of the light.

pesty

Charging while running is going to depend on the light... some will, some won't. My current Garmin UT800 will not.

As for the generic 18650 lights... I personally would avoid any of the ones with the spherical lens, or any of the really cheap ones.

That being said, I did use a NiteCore SRT7 for about a year and a half and found it to be a great light (used an SRT5 with a 14500 battery before that, but it was a little weak). It's not cheap, and it's a pretty tightly focused beam, so it works well on road at speed. One thing I specifically liked about the SRT series was that the output is infinitely adjustable between nearly nothing and full power. The downside is it's fairly heavy, so finding a good mount took a lot of trial and error. I finally settled on a mount off of ebay that allowed me to put it on a K-Edge style GoPro mount. The only reason I'm not still using it is because I wanted something smaller, lighter, rechargeable without removing the batteries, and had ANT+ connectivity to my Garmin.

Canker

Guy I mountain biked with did that with one of his lights were the built in battery had completely died, no longer charged. It "worked" but only on the low setting. The external battery couldn't pump out enough amperage to run the light at the higher settings by itself. I just use the sketchy Chinese lights and external batteries.

Tourist in MSN

I bought a similar light, no battery, just powered by USB cord. The one I got had a single LED and reflector, not two, and it also was about $5 USD. It was described as having high output, low output, and flash mode. I found that it was worth the $5 USD that I paid, but it had some problems when I tried to run it off a dynohub without a pass through cache battery. When you stopped, it lost all power. When you start riding again, you had to get up to a good speed (I do not recall the speed, maybe about 10 mph) before it would light up enough to be able to change modes because it always started in high power mode and with less power out of your dynohub at a slower speed it would not provide enough power to the light to allow you to switch to the low power mode. Once in low power mode, you could go slower and keep the light lit, say if you were going slowly up a hill. But if you got too slow, the light would lose all power and then you would be in the dark.

But to run it off a powerbank, it would have worked great. It also would have worked great on a dynohub with a pass through cache battery to keep the power up while you slow down for hills or stop for stoplights.

I might bring it on a bike tour because on bike tours I almost never ride in the dark but occasionally need a light for tunnels, etc. And then I would only use it on a power bank for short periods of time. On bike tours I am almost always charging batteries off of my dynohub.

It is a symmetrical beam similar to a flashlight, not a low and wide beam like the better bike lights. But for $5 USD, you can't be too picky.

The one I got was like this one:
https://www.ebay.com/itm/New-Waterpr...t/192394993651

angerdan

B&M Ixon Core can be charged while powered on.
bumm.de/en/products/akku-scheinwerfer/parent/180/produkt/180l.html?

SylvainG

Why not have both? A rechargeable USB light and the convenience of swappable batteries?

https://www.cateye.com/intl/products...ts/HL-EL471RC/

angerdan

How do you know it can be powered on while charging? Cateye don't write anything about it, so i bet it isn't possible.

canklecat

My 2016 version of the Light & Motion Urban 500 cannot be charged and run simultaneously from an external USB battery. No idea about the other L&M lights but it's likely all of the Urban series are the same, at least up to the 2016 models. You could email L&M to ask about this. Great lights otherwise.

My various to-be-seen lights can be charged and run simultaneously from external USB batteries:
Vivo Bike Illuminati (now available on Amazon under various other names)
Blackburn 2'Fer
Cygolite Hotshot 50

In fact, all of my other USB rechargeable devices can charge and run simultaneously, including my video camera, cell phones, etc. The L&M Urban 500 is the one exception.

I usually carry a Serfas SL-255 headlight as a backup. It runs on AA batteries, including NiMH or other rechargeables.

Relying on external USB batteries as a backup has limitations, primarily lack of weather resistance. On all my devices it requires opening or removing a weather seal to access the USB port. The batteries themselves aren't usually rated for wet weather. And the cords and plugs can be fiddly, snagging or eventually loosening and losing connection.

Since I ride at night more often than I'd expected after resuming cycling a few years ago I'm considering a dynamo setup for my hybrid used for casual rides and errands.

noglider 

I have one of these. It's an excellent product. In this linked page, it shows the mount with the knob, which I'm sure is good. I got the rubber band mount which allows the light to slip down. That's my only complaint. The beam is extremely well focused. The battery life is tremendous. The battery life indicator helps a lot, as it shows five levels. I usually commute on a bike with a dynamo, so I use the Ixon Core only on my racing bikes, because I want to keep them lightweight.

angerdan

Only my cheap chinese FisherMo COB FMCD004 can charge and run simultaneously. Knog and Cateye don't.

Powerbanks can be stored in frame bags, so that the only exposed part would be the connection on the light. Cables can be fixed to the frame or replaced with coiled cables.
Delock Produkte 83162 Delock Kabel USB 2.0-A Stecker > USB micro-B Stecker Spiralkabel
Delock Produkte 83249 Delock Kabel USB micro-B Verlängerung Stecker / Buchse Spiralkabel

SylvainG

Just tried and you can't (on mine at least). Point is, instead of carrying a USB backup battery to recharge your light as it runs, get a spare battery and when the first one drains, swap it for the fresh one.

PaulRivers

As people have said it varies, some let you charge while riding, some do not.

When I go mountain biking near dusk I need to have enough light to get out of the woods. So to cover all backup scenarios (including my main light getting broken) I bring a backup light. A Fenix BC21R is the smallest (including mount) light I was able to find at the time for $75:
https://www.amazon.com/EdisonBright-...dp/B01ACHGGQW/

angerdan

In a german Forum a mamber did find out that the B&M Ixon Space can be charged while powered on too (like the Ixon Core).
https://www.bikeforums.net/commuting...ot-lumens.html

GadgetGirlIL

The new Light & Motion Rando can be charged while using it. I've ridden in the dark several times with it and really like the light pattern.

https://www.lightandmotion.com/rando-500

The only thing you need to remember is if you want to charge it when you aren't planning to use it, you must use the orange ended USB cable that comes with it! Otherwise the light stays on. A little annoying when you are in a hotel room...