# Cold weather battery issues



## Lagopus Lagopus (Oct 3, 2011)

I have a cygolite 740 turbo. When it gets cold (below 5 degrees or so) battery life drops dramatically. Yesterday, at 10 below, I only got about 20 minutes on the low setting, from a full charge.
Anybody have better experience with a light they would like to reccommend?


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## indebt (Nov 8, 2009)

Hey Lagopus Lagopus, i had the TridenX Extra 4-cell. I believe the Turbo 740 is using the same battery's whether it is the two or four cell version. I did a ton of winter riding with that set up and had no battery issues. That been said it's pretty mild here in Squamish BC most of the time as i'm on the Pacific coast and am riding in tempuratures no lower than approx 25 degree's F. I think you must have a faulty battery as 20 minutes reguardless of temp is not what any two or four cell should be providing. Now if your riding at temuratures of -10F??? yes that's freeking cold and will effect the battery somewhat and steps should be taken to shield the battery from the cold. I would give it another try first by using your warrenty and getting another battery. The only other thing i can think of is the battery was drained to far or charged to high which also would damage the battery. That would then be a faulty charger or internal electronics not shutting the light off before battery damage.


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## Lagopus Lagopus (Oct 3, 2011)

I don't think it is a faulty charger, or internal electronics because i get good run time when it is warmer. Yesterday it was fully charged when i set out in the daylight. after an hour or so of riding it started to get dark, and i turned on the light. I immediately got the blinking low battery indicator, and it only ran for 20 minutes before it died completely. The battery was mounted on my handlebar, and not protected from the cold. On other cold weather rides, when i start in the dark and turn it on immediately i get up to an hour of battery life, on the low setting.
I have already decided to replace it, but want some feedback from other cold weather users, in deciding what to replace it with.


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## jugdish (Apr 1, 2004)

FWIW, I put my battery somewhere relatively warm until I'm ready to use (bike/ski) it. I also put them in koozies to keep them warm(er). I have no idea whether this has any scientific worth but it seems to work for me.


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## Vancbiker (May 25, 2005)

Discharging at High and Low Temperatures - Battery University

A good read on this very issue.


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## indebt (Nov 8, 2009)

Lagopus Lagopus said:


> I don't think it is a faulty charger, or internal electronics because i get good run time when it is warmer. Yesterday it was fully charged when i set out in the daylight. after an hour or so of riding it started to get dark, and i turned on the light. I immediately got the blinking low battery indicator, and it only ran for 20 minutes before it died completely. The battery was mounted on my handlebar, and not protected from the cold. On other cold weather rides, when i start in the dark and turn it on immediately i get up to an hour of battery life, on the low setting.
> I have already decided to replace it, but want some feedback from other cold weather users, in deciding what to replace it with.


 What is your budget and output expectations? The Xera so far seems really good and i've had no issues with it down to 24degree's F, or -5C, plus is in the same price range as your 740. With a higher budget there is so much to choose from. My primary set up are Lupines and cant say enough good things about them, but of coarse are very expensive. Here are a few i think are quality products and backed by good company's. Are you riding in -10F,or -10C??? Big difference between the two,but very cold either way and battery protection would help alot reguardless of your choice.

- Amoeba!! Scar will customize to whatever configuration your looking for, and will be there well after your purchase. May even be able to put extra battery insulation for more protection from the cold

- Any of the Bajadesigns products will give you the durability you should be happy with. Shannon may also be able to increase battery protection.

- Dinotte Xm-L3 is another high quality light and very well priced.

There are so many more to choose from, but these three are a good start. I can say that from all the lights i've used, repetitive rides in cold weather has decreased run times a little bit along with age and cycles. Alway best to get a battery with extra capacity as they are going to loose some with use, age,and ambiant tempuratures you ride in.Cheers!!!


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## jugdish (Apr 1, 2004)

Vancbiker said:


> Discharging at High and Low Temperatures - Battery University
> 
> A good read on this very issue.


 "Cold temperature increases the internal resistance and diminishes the capacity. Batteries that would provide 100 percent capacity at 27°C (80°F) will typically deliver only 50 percent at -18°C (0°F). The capacity decrease is linear with temperature."

Score one for dumb luck!


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## Cat-man-do (May 16, 2004)

Lagopus Lagopus said:


> I have a cygolite 740 turbo. When it gets cold (below 5 degrees or so) battery life drops dramatically. Yesterday, at 10 below, I only got about 20 minutes on the low setting, from a full charge.
> Anybody have better experience with a light they would like to reccommend?


First you need to clarify what temperature scale you are using ( F. or Celsius ) so everyone is on the same page. Dude, if you are riding at -10°F you are one hard core fellow! :lol:

Years ago I used to try to do rides with temps in the lower 20°F range. Even at that temperature the voltage monitor leds on the light heads go ga-ga and the run times are generally shorter. I tried everything I could think of to insulate/isolate the batteries....I wrapped them in thermal foam and used an insulated battery bag. Nothing I did seemed to make a whole lot of difference. I even tried chemical hand warmers. Unfortunately those don't work well unless they get a good supply of oxygen.

One of the problems is the battery cord itself. The wire gets cold and acts as a heat sink. Eventually the cold travels all the way to the battery. As far as bar lights go there doesn't seem a whole lot you can do other than carry a spare battery inside your jacket ( next to your body ) and switch out after about a half hour. Even so, I doubt this will work well at minus 10°F.


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## pethelman (Feb 26, 2011)

*One more thing to consider...*

Don't forget that if you're charging the battery at a cold temps, the amount of "full" charge will be limited as well. Charging in a cold garage, bad... charging inside at room temp, good!

Also, if you're serious about riding in the cold and need the batteries to stay warm, you might try putting it in a sock with a few of these:

http://www.amazon.com/HeatMax-Hot-Hands-Handwarmer-Pairs/dp/B0007ZF4OA

They work amazingly well. Just above body temp heat for hours and activated by air.
JFWIW


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## Lagopus Lagopus (Oct 3, 2011)

Cat-man-do said:


> First you need to clarify what temperature scale you are using ( F. or Celsius ) so everyone is on the same page. Dude, if you are riding at -10°F you are one hard core fellow! :lol:
> 
> Years ago I used to try to do rides with temps in the lower 20°F range. Even at that temperature the voltage monitor leds on the light heads go ga-ga and the run times are generally shorter. I tried everything I could think of to insulate/isolate the batteries....I wrapped them in thermal foam and used an insulated battery bag. Nothing I did seemed to make a whole lot of difference. I even tried chemical hand warmers. Unfortunately those don't work well unless they get a good supply of oxygen.
> 
> One of the problems is the battery cord itself. The wire gets cold and acts as a heat sink. Eventually the cold travels all the way to the battery. As far as bar lights go there doesn't seem a whole lot you can do other than carry a spare battery inside your jacket ( next to your body ) and switch out after about a half hour. Even so, I doubt this will work well at minus 10°F.


It was -10 F. Of course I expect some shorter run times at that temp, but my light was totally useless. I guess my real question is do I have a battery with a manufacturing defect, or is there a design flaw in all of the batteries in this line? And which lights do run best at cold temps.


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## mattthemuppet (Jul 16, 2004)

I thought Scar posted up a chart showing that lithium based batteries still get 90% of capacity at 0F. I've ridden several times at 0F and, even though I couldn't feel my fingers or toes, my batteries were fine. I wasn't out long enough (>1 1/2h) to run them down completely to see how much lower the capacity was though. -10F I have no experience of, but the curve didn't seem particularly precipitous (nickel based batteries OTOH had 5-10% capacity at 0F).

Difficult to know if it's a warranty issue (bad cell/s) or more a consequence of the cells they use.


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## gmcttr (Oct 7, 2006)

Lagopus Lagopus said:


> It was -10 F. Of course I expect some shorter run times at that temp, but my light was totally useless. I guess my real question is do I have a battery with a manufacturing defect, or is there a design flaw in all of the batteries in this line? And which lights do run best at cold temps.


From the Battery University link in post #5..."The performance of all battery chemistries drops drastically at low temperatures.* At* -20°C (*-4°F*) *most* nickel-, lead- and *lithium-based batteries stop functioning*."


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## mb323323 (Aug 1, 2006)

It probably has a bit to do w/ the age of the battery as well. An older battery is going to be more affected.

My newer batteries (Dinotte) work well so far and have not had any run time decrease in the cold that I can tell. I charge them and store them in my garage however, Bay Area so my garage probably doesn't get below 50 degrees F and it would be rare to ride in anything below 40 F so I am probably not a good judge on this. My experience anyhow.

MB


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## Cat-man-do (May 16, 2004)

gmcttr said:


> From the Battery University link in post #5..."The performance of all battery chemistries drops drastically at low temperatures.* At* -20°C (*-4°F*) *most* nickel-, lead- and *lithium-based batteries stop functioning*."


Strangely, Battery University did seem to contradict itself in the short article. In the second paragraph they state,



> Cold temperature increases the internal resistance and diminishes the capacity. *Batteries that would provide 100 percent capacity at 27°C (80°F) will typically deliver only 50 percent at -18°C (0°F). The capacity decrease is linear with temperature.*


Then they state....



> ....*The performance of all battery chemistries drops drastically at low temperatures. At -20°C (-4°F) most nickel-, lead- and lithium-based batteries stop functioning.* Although NiCd can go down to -40°C (-40°F), the permissible discharge is only 0.2C (5-hour rate). *Specially built Li- ion brings the operating temperature down to -40°C, but only on discharge and at a reduced discharge.* ....


First it was stated that a Li-ion battery is down to 50% capacity at 0°F and then they state they will stop functioning at -4°F...:skep:...that doesn't sound "linear" to me. 
Interestingly, they then mention that "specially built" Li-ion batteries can be designed to discharge at -40°C but only at a reduced discharge rate....Okay, so now what to think about the Li-ion batteries that we own? :skep:

One thing we do know. Cold effects the function of the battery chemistry.
Additionally, it needs to be pointed out that since most Li-ion battery packs are using multi-cell configurations there is a good chance that operating a Li-ion pack at extreme low temperatures will heighten the chance that the pack will develop an internal short within one of the cells. The deeper the discharge, ( at extreme cold ) the higher the chance of permanent battery pack damage/failure. If you really want to ride in extremely low temperatures you need to isolate the battery from cold as best as you can if you're going to use Li-ion batteries.

*LL*...it could be that your battery is already damaged, hence the shortened run time. Do an inside the house charge/runtime test. Hopefully your battery will still work at normal temperatures.

One idea I had that I never tried: I always wondered if wrapping the battery in one of those battery powered heated socks would help. You would still need to pack the battery/sock in something wind-proof and insulated. Now if can find a way to insulate the wires....some type of foam tape wrapping...:idea:...just a thought.


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## mattthemuppet (Jul 16, 2004)

anecdotal evidence would suggest that li-ion and li-po batteries work fine at -4F. mine do, all my riding buddies batteries work, even Scar gets out and about in those temperatures and worse and he's had more batteries pass through his hands than I've had hot dinners. Additionally, I've never noticed mine or others li-po phone batteries going flat or substantially reducing in capacity on a ride.

my guess is a problem with the battery.

oh, and another tip for cold weather riders - don't charge your batteries as soon as you come in from a ride. Let them warm up first (an hour or so) so that there's no risk of condensation forming inside the pack.


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## MtbMacgyver (Jan 23, 2007)

Cat-man-do said:


> First it was stated that a Li-ion battery is down to 50% capacity at 0°F and then they state they will stop functioning at -4°F...:skep:...that doesn't sound "linear" to me.


I can't really speak to the accuracy of the specific temperatures listed in the battery university info, but li-ion response to cold isn't linear. It gets rapidly worse as you go below 0 degree F.

Also keep in mind, it's not the outside temp that matters. It's the temp of the materials inside the cells. So factors such as how long it's been since the battery was inside a warm place and how the battery is packaged make a big difference. If the battery pack is left outside for many hours in below 0F then it's not going to work well at all. It's a different story if the battery is inside a warm place and then immediately taken outside for a ride. Also, never charge a li-ion pack with the internal temp of the pack below freezing. It will ruin the pack. The protection circuity for very high quality packs will actually prevent charging if the internal pack is too cold.

I ride some in temps close to 0F on occasion. My solution is to primarily use a helmet light and keep the battery pack in my jersey pocket under outer clothing where it stays at a reasonable temp. Then I get pretty much normal runtimes.


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## Lagopus Lagopus (Oct 3, 2011)

I decided to return the cygolite (thank you REI) and ordered a Dinotte. Two xml-1s. One helmet one handlebar. On cold days I can run just one, and keep the spare battery in an inside pocket. Hope that works. Thanks for all the information and insight on batteries!


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## Cat-man-do (May 16, 2004)

MtbMacgyver said:


> ...I ride some in temps close to 0F on occasion. *My solution is to primarily use a helmet light and keep the battery pack in my jersey pocket under outer clothing where it stays at a reasonable temp.* Then I get pretty much normal runtimes.


Yep, sounds like a good idea. Another good idea might be to try running a self-contained torch or light on the bars. I'm going to try covering a torch on one of my next cold weather rides to see what happens. Usually you would be worried about it over-heating if the metal was covered but in this case it might be possible to use the heat generated by the LED to heat the battery tube, thus keeping the battery warm. I'll give it a try and let you know how it works.

I just purchased another XM-L torch that contains the same voltage feedback indicators as most bike lights. On the last ride I went out on ( with freshly charged battery ) the voltage indicators went to red after only a couple minutes. This just goes to show what cold does to the internal resistance of Li-ion cells. All I have to do now is find something that will cover most of the torch without interfering with the mount. ( my new torch > Link > *notice the neat swivel mount below in the link...very nice it is. )


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## scar (Jun 2, 2005)

*Great topic, I guess it is time to chime in*

Been kind of holding off on making any statments as those are some crazy temps to be riding in and I have no experience going that low. The lowest me and my buddies have gone is 7 degrees F. Also, here in Denver the humidity is about 0 so that helps out alot.

I have also been waiting to hear back from a new customer that I just shipped a light to in Anchorage, AK. I am pretty sure he is mounting the battery on his helmet out in the open. He has been out with it a couple of times now and sent me the following -










_"Glad to have your light on my head as my other one crapped out early on. This is getting towards the "fun / no fun" temperature limit for me. At these temps there is a lot of rolling resistance in the system - stiff tires, thick grease, Michelin-man clothes and general lack of initiative all of which conspire to make you feel even more out of condition than you are."_

Keep in mind this was a brand new battery pack. But it is great news 

I am not sure if he hangs out/posts on MTBR or not. I will ask him if he does and ask him to give his input on the subject.

***


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## Stroganof (Jan 28, 2006)

The only battery problem I've had in the cold is my Garmin gps running out of power very quickly. But when temps are zero and below I rarely ride for more than an hour or so, but have had no issues with lights working other than a particular light head giving it up last night (but have had no issues with another light head of the same brand and suspect that the new one is defective).


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## mattthemuppet (Jul 16, 2004)

scar said:


> Been kind of holding off on making any statments as those are some crazy temps to be riding in and I have no experience going that low. The lowest me and my buddies have gone is 7 degrees F. Also, here in Denver the humidity is about 0 so that helps out alot.
> 
> I have also been waiting to hear back from a new customer that I just shipped a light to in Anchorage, AK. I am pretty sure he is mounting the battery on his helmet out in the open. He has been out with it a couple of times now and sent me the following -
> 
> ...


that is bloody cold for sure  I thought I saw pics of your stem cap thermometer showing less than 7F? Mind might be playing tricks with me.

Anyway, what you really need at low temperatures is not more light, it's more RUM! Nothing like a sip of the stuff at the top of a snow covered mounting in complete darkness with a good mate or two


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