Should I buy LiFePO4 battery or other low-temperature battery for winter travel? The lithium battery used at cold environment decreases the discharge rate, is that true?
While I don’t know the battery you refer to, I can vouch for the fact that lithium ion batteries discharge much more rapidly in extreme cold. I used to fat bike in the snow at night in Eastern Canada and around -15 to -20c I found my bike lights discharging in about a third of the time compared to warmer weather.
I've taken plenty of pictures on Samsung S5/S8 phone at -20 to -30. Obviously you keep it in inside pocket close to body heat. But at same temps, contemporary model iPhones fail within seconds. Might get one pic if you're quick before it shuts itself down. At the LL downhill, super low temps are a common occurrence. One of the classic tactics was to tape a pair of chemical hand warmers around your VHF radio battery to extend its life on cold days. Nowadays they have lots of collar mikes available so the radio itself can be kept in an inside pocket. In general, yes, Li ion batteries have shorter life in low temp, but that goes for all batteries. Nice thing with lithium is delivered voltage stays close to nominal right until end of capacity, whereas NiCd and NiMH show noticeable voltage drop and resultant degraded performance in the final third of their capacity. When we switched to lithium system for cordless tools at work, one of the big pluses was their greatly superior cold weather performance.