Freezing taillight

[Juha]

Cheers everyone. We've had a cold spell lately and I've been on bike almost every night, coming home from hobbies and whatnot. Last week I noticed my rear blinkie getting weak, so I replaced the battery. Yesterday evening I noticed the blinkie getting weak again. When it's warm it works OK, but after one hour in the cold (-20C or thereabouts) it's noticeably weaker.

The light is a Basta Rugby, operating on a "coin" type battery (I forget the type). It may be a bad battery of course, but it occurred to me that as the entire light is small and lightweight by design, it gets very cold very quickly. Apparently freezing the battery to -20C every day, sometimes twice a day, kills it in no time. I have not noticed this before, as I really have not done repetitive longer trips in such consistantly cold weather and in the dark.

Does anyone have any experiences as to what kind of taillights tolerate cold weather better? I need to be able to mount it on backpack, seatpost, bungee cord or wherever needed, so I guess a dynamo operated tail light is not an option. The Basta has been extremely flexible in that regard.

--J

[slvoid]

Get a new light that uses AA or AAA's. Then get a set of lithiums. They're good down to -60 without dropping their voltages.

[Diggy18]

I have the same problem with my front LED Catseye blinkie. Maybe in the teens (f) or so it stops working, but seems to come back to life when it gets warmer.

Can you wrap part of the light in an old sock with a hole cut out for the light? Haha, guess you can't wrap the whole light in a big sock, eh?

[2manybikes]

It's the batteries not the lights.

Cold stops some chemical reactions (like inside alkaline batteries). Follow slvoid's advice it works.

Lithium batteries.

If you have used fairly new Alkaline batteries in the cold and they don't work, save them for the warm weather, they will work again.

[Michel Gagnon]

Even between alcaline batteries, there are lots of differences between models.
I found that Duracell AA batteries don't last in cold weather, but that Energizer batteries still have a decent lifespan at -10 or -15 C. Their life shortens after that, but still to acceptable levels.

Since it's easy to get affordable AA and AAA batteries around here, I haven't been tempted to buy lithium batteries. But if I were riding at -30 to -40 C, I would.