Before I try contacting support I thought I would see if anyone here might know what is causing this problem. I have an almost new Cygolite Dual Cross Li-ion. Used it a couple of times with no problems. Then about a week ago I charged it full, then left it on the bike overnight like typical. But in the morning something came up where I needed to drive to work, so I left it fully charged on the bike and didn't think a thing about it. I had planned to ride this morning, so I topped it off with a quick charge (the instructions stated it was okay to do this) because it had been sitting for a long time in cold weather and I wanted to make sure it was fully charged again. I started riding and in about 5 minutes it started flashing and shut down. Drove to work again and then this evening I tried it again and it did the same thing. Tried charging again....the green light indicating full charge comes on in just a couple of minutes. So I tried the light again....same thing. In fact, after trying to turn it off and on several times it finally got to the point where it wouldn't even come on at all.

Any clues? Was topping off when probably close to full charge the problem? Or is it just an overall issue with either the light itself (processing chip?), the charger, or the battery? Anybody else have one of these?

Thanks very much ahead of time for any input.

i would call it in...they are pretty good about picking up their phones.
they can probably tell you what it might be.

I have the same light (Pro version) and unplug the Li-Ion battery from the light when not in use. Any solid state switch allows some current flow, so disconnecting the battery stops that. There is a diagnostic mode to check if the light is defective. Contacting Cygolite folks is your best option.

My gut says that the battery somehow got toasted, but calling into Cygolite is the most sensible thing to do.


I have the NiMH battery version. I don't know whether it is relevant or not, but just as a matter of habit I always unplug the battery from the head when I am not using it. Come to think of it, I don't recall how you turn it off using the buttons on the top - if I am riding to work in the morning and have it on for part of the way, eventually I reach a spot where I no longer need the light, and I just reach down and pull the plug out.

Good advice, and thanks again to everyone. I called them and they said to send it in, they will fix for no cost....without the original receipt (I bought on Ebay). So far, so good. I'll post the results as they unfold for those of you interested in Cygolite's customer service.

A follow up for those interested....I just received the repaired light yesterday. No charge. They replaced the charger....which surprised me. I would have thought it was the battery or the circuitry in the light itself. I did a short run test and it seems to be okay. I will post another follow up after the first ride to test for extended period.

At this point, I would give their customer support at least a B+. It did take quite awhile to get the light back, but considering the fact they told me it would take awhile over the holidays....and that they didn't charge me anything with no receipt.....I am very satisfied. I'll be ecstatic if this fixes the problem long term.

Seems to be fixed completely. I used it for an entire charge and it performed perfectly. Hopefully that problem will not resurface. I give a big thumbs up to Cygolite for service. :beer:

Good to here.

Was it the PRO dualcross or just the dualcross. I'm thinking of adding the Pro on the helment with my Cygolite TridenX on the bars.

It is not the Pro. Just the lithium version of the original dualcross. I can't imagine the Pro with a Tridenx....that's gonna throw a lot of light!!!

Thanks for the response.

I don't think it will be to bright for mountain biking it's nice to have a spot beam for the single track.

As for my commute just the TridenX on high. I have to say I really like the wide beam for commuting even after retiring my L&M ARC at 675 lumen's VS. the wide beam of TridenX at around 500 lumen's. The wide beam is perfect for my commuting needs. It just seems to get notice more buy drivers pulling up at side streets.