On my commute yesterday morning my fully charged lights packed in after only half an hour. Given it was -5 at the time and my front light is an Amazon £20 special I wasn’t too surprised, however my expensive Lezyne rear light packed up as well.
Fortunately my cheapo little flashing Spinnega lights held out and saved the day. Well allowed me to be seen rather than see where I was going.
Any recommendations on decent front and rear lights that will last a bit longer in the cold? Or any tricks to somehow insulate the lithium battery pack for my front light at least?

Bosch sell an insulating jacket to cover the battery on their ebike, so id be thinking along those lines.
How about putting the battery pack inside an old glove to protect it from the windchill?

Sub zero screws up Lithium cells.

Less so alkali.

Get one of those little top tube food bags and stick it in there.

I’m not so sure there’s not something else wrong with your battery though. Mine aren’t that badly affected at -5c.

3 posts and no one’s moaned about “effecting” yet. I’m disappointed.

This is where the all-in-one designs win as the heat of the LED warms the battery preventing capacity drop in low temps. You can try insulating the battery pack but I found the best way with separate batteries was to stash them in your jacket, letting your body temp keep them warm.

Another advantage of the no lead technology in use exposure kit.

The heat generated by the light keeps the battery warmer.

Commuted in -10 without any hassles. My helmet cam gave up in about 15 minutes mind.

3 posts and no one’s moaned about “effecting” yet. I’m disappointed.

It’s the social media affect, innit? 😉

Were they cold when you turned on (i.e. already cold from being stored on the bike in a cold place) ornwere they room temp when you set off?

If not already, might be worth setting off with them at room temp, then the heat generated from discharge might keep them going much longer (assuming they are reasonably powerful lights and you normally get much longer than half an hour)

.

And as above ref all in one units

Firstly apologies to the STW grammar police ;0)

Stored inside so nice and warm to start with. Good shout with an all in one, just not got the same burn time though without spending a small fortune I’ve found.

The chemical reaction in li-ion batteries is temperature dependent, so it’s not a case of cheap vs. expensive, it’s a fundamental limitation of the technology.

So as above, all you can do is try and keep them warm by wrapping them in something and keeping them somewhere warm when you’re not riding.

It’s worth pointing out that you’re not actually draining the battery when you get it cold. You should find that when it warms up again it’s still got charge. Sometimes when I use my camera outdoors in cold weather, I need two batteries. Once one appears to be dead, I swap it for one keeping warm in my pocket. When that cools down and “dies” I swap it for the previously “dead” one which has now warmed up and come back to life.

My nitenumen x8 all in one gives a good 2.5 hours on max, or 4ish on medium – which is what mine mainly stays on – it’s fine to see by when road riding on unlit roads, only going to max on fast downhills. 1800 claimed lumens, probably my more like 1200.

For commuting the best option is a dynamo, no worries about batteries and not affected by the cold.

In really cold in Finland I bubble wrapped my batteries, popped a heat pack inside and chucked it all in a dry bag. They worked a treat.

Sub zero screws up Lithium cells.

Less so alkali.

Wrong.

Lithium for colder temps. Cr123 will go to -40. Alkali around 0.

At -20C the life of a lithium battery is effectively halved, hence best to keep battery packs inside clothing. On my first winter trip to the arctic I got 7 hours out of a 12 hour battery pack.

Stored inside so nice and warm to start with. Good shout with an all in one, just not got the same burn time though without spending a small fortune I’ve found.

Probably depends what you’re looking at. I’d agree that if you’re looking at off road lights in excess of 1000Lm, but I ran a Lezyne Macrodrive for a couple of winters with no issues.

What sort of burn times are you expecting from a commuting light?

Well I need three hours (1.5 both ways) and have had this when it wasn’t so cold without any bother. Parts of the journey are on stretches of completely unlit roads with the usual potholes / craters / grand canyons which if i found myself hitting, my bike and body would be in bits.
100% road though. I can get away running my light on its lowest constant setting and there is enough light, just disappointed the battery drained so fast.

CraigW – Member
For commuting the best option is a dynamo, no worries about batteries and not affected by the cold.

This. It also means that unplanned pub stops in summer are not an issue. And although the lights I’ve had haven’t been 100% reliable, they’ve been massively more reliable and durable than anything except Lumicycle.

Problem is my bike is my only road bike ( Cannondale Super Six ) which is use for fast club runs and training on. Don’t really fancy a dynamo, are they not cumbersome and heavy?

Modern dynamo hubs are much better than of old. I have the Schmidt SON 12mm dynamo on my Bokeh and I don’t even notice when its drawing power. It is a bit heavier, but not excessively.
I use it with a B+M lamp which has an integral USB output so on touring/ multi-day trips I have a USB battery pack plugged in to charge. I have a rear lamp as well, but it won’t standlight unfortunately which is annoying so I have an additional USB flasher to cover stops.
Herself has a SP 15mm dynamo which has been very reliable – she commutes using it, powering the same B+M lamp as I’ve got.

Front hub dynamo might well beyour real answer… three hours is quite an ask without expense creeping in although manually managing power will help a lot.

That said, decent fun dynamos aren’t peanuts either.

Yeah just been looking at dynamos, not cheap and would need to pay a shop to fit as well, and given the state of my winter wheels I’d be looking at getting a new rim also.
I like the idea and will probably go this route in future but can’t afford it just now.
I think an all in one unit will be better than I currently have and if I get a second charger for it I can top them up at work to get me home.
Exposures get great reviews, any others I should be looking at? Preferably slightly cheaper.

>rong
Oh, really? Maybe different types of Li cells? My phone warns not to get it below 0.

A little knowledge etc etc

My GoPro alike battery was showing it was dying last week, but it never actually did. Once inside it was showing full power. I suspected the cold at the time.

Nah just get a light with a bigger battery. They are pretty cheap these days.

I’m using a Lezyne macro drive 800XL, it could do with a bit more spot but it’s bright and gives me enough options. 3hrs at 500lm IIRC but 7 at 300 I think. So in the cold I could just use a lower setting.

Lithium good at lower temps?
Really?
Have to tell our hybrid battery guys they don’t need to spend anything developing strategies to keep the battery warm when it’s cold out.

😕

IIRC it’s about a 40-50% loss of rated power once the battery is soaked down to 0 deg C (rated power is quoted at something like 20 or 25 deg C).

I’ve double sleeved the 2×18650 pack i use 1x heatshrink tape, 2x layers of 3mm neoprene. And stick one of those rechargeable heat packs between the two layers of neoprene when it gets really cold (below -10ish)

I would suggest charging the batteries when they are at room temperature, rather than plugging them in as soon as you take them off the bike.

Also, insulating will only help if the batteries start off warm, and/or generate enough heat from discharge to keep warm. Windchill will increase heat loss, but once the battery is the same temperature as the air, insulation does nothing.

Its like insulating cold water pipes in an unheated builder…it will slightly delay freezing but then massively increase the defrost time…

Most battery’s are shit at colder temps. However, Lithium is less shit than alkaline or Nickel–cadmium.
Plenty of info available If you care to search.

A ten second search found this

Click.

This week my Exposure turned itself off during my 3hr night ride in 0 degree temperatures. Whereas the same ride the previous week in positive temperatures it was fine. Charged all day prior to both rides.