Oh yeah. Depends how cold you thinking. The drop can be pretty high when goes below 0. Mostly you can feel the drop when starting to drive.

Should add that if you have the battery inside where warm and go out to drive then you can have same kind effect like summer time. But if living the bike outside longer or about 30 minutes or more at -3 "starting" then most sure you start feeling more worse effect. This is how i know of lifepo4 battery's.

Luckily I don't have this issue in Australia...rarely gets bellow 4'C here and I store the bike in warm garage...so not seen any difference... now I'm starting to get weather in the 30-40 'C I might be able to comment on the other extreme, will keep you posted...

Lol. You we'll come up here ;)

I came from the UK so have history with cold weather, that's why I left..... :-)

Cylindrical and prismatic cells have a liquid electrolyte. The lithium ions have to pass through the electrolyte when you are charging or discharging. And if the electrolyte freezes is not easy for the positive ions to move, they found more resistance that is experienced by you as voltage drop. LiPo cells have a polimeric electrolyte filled with a gel that should have a lower freezing point, but to be honest I don't know how much lower it is. Moreover less temperature means less activation energy for chemical reactions and you have less capacity for the battery when it is used in cold environment. Of course when the battery ages its internal resistance increases too and this can be added to the cold temperature effects.

This is a 36v-15AHr, NMC, aluminium cased battery to go in a rack. I've been inside and it's shrink wrapped and I think prismatic cells. Now, I thought all current LiOn batteries used a gel so are technically LiPo even though that term is usually used for RC LiCo (Lithium Cobalt) packs made up from cylindrical or pouch cells.

I don't think the battery got frozen as the temp was around 0C rather than below. So the effect was probably mainly slower chemical reactions and sluggishness. The battery is now 2 years old. I don't know how many full cycles it's had and anyway I only rarely run it down. Mostly it gets fully charged every 10-15 miles. These NMC batteries are advertised as 1000 cycles compared with 2000 for LiFePo but they're also 2/3 the weight/volume and 2/3 the price. I figure I should get 3 years out of it, and maybe 5.

I took it out yesterday for a 10 mile run (3-5C temp) and while voltage drop under load was significant, it hasn't obviously lost any capacity. So I reckon, while it probably is showing its age, it's still fine. It just doesn't like the cold.

Yes I agree with you that the slowing of the chemical reaction can be the main reason. On the other hand the ohmic resistance of the metal components such as cables goes down with the low temperature, but evidently this effect is much lower than the temperature effect.

Before I said that the capacity of the cells decreases with the decrease of the temperature. If we look at this curves http://www.rfcafe.com/references/electrical/images/li-po%20discharge%20curves%20at%20various%20temperatures.jpg we can say that also the internal resistance of the cell decreases, so it should be this the reason of your experience

My bike is stored in a garage so I generally find my range is the same in the cold.  Mind you, our cold weather has only been around -2c at worst.

Sure, the cold does make a difference. Most manufacturers do point that out. My own experience is that with outside temps being not less than 12c its marginal. At 6c, the drop off in kilometres I reckon to be about 10% against a 12c period. Even then (over a 6c period)I am still getting 80+ kms on a charge over mixed terrain. In summer (18-24c) it was regularly over 100kms. I have a Qwic Urban 20" wheel folder.

they might start building in battery warmers for this sort of issue.. ;-)