The charger is disabled below 32F? >_< how are you suppose to charge the bike in winter move the bike indoors? I have a garage but I can tell you it gets colder than 32F in there. Is it a fault in the charger or is it a problem in general of charging Liion batteries in cold weather? I find it odd that you can discharge the batteries but not charge them
Charging indoors may be an option for some people.
It's not an option for me; I park my bike outside @ work and in an unheated parking garage @ home. In my case, I don't ride far enough for range to be an issue .. and can charge every few days when the temperature rises above 30F.
Generally speaking, lithium cells can be damaged when charging in cold temperatures. It is partly for this reason that many electric vehicles include heaters for the batteries .. plugging in to charge will first activate the heaters, then begin charging the battery when the battery is sufficiently warm (> 32F). Unfortunately Zero does not build cell heaters into their battery packs.
If ambient temperatures are fairly close to 30F, then it may be less of a concern - discharging the battery will heat the cells above ambient, and plugging in to charge will also generate some heat that will typically keep it above ambient.
For example, let's say it's 25F when you leave work. Riding for 20 minutes back home will heat the cells (say to 40+F) .. then when you plug in at home in an unheated garage, the cells will be kept above 32F due to heat generated while charging. If the cells do drop below 32F then the BMS will disable the charger to prevent damage to the cells.