Generally, storage or use at cold temperatures shouldn't be an issue, as long as the battery can still deliver enough power to operate the tool effectively.
Charging though...at cold temperatures, ion mobility goes down. If the battery is charged too fast, the lithium ions can't make it into the graphite anode fast enough and they start to plate out as metallic lithium. At best, this results in a permanent reduction in capacity. Next worst from there, the lithium metal can create an internal soft short, immediately or at a later point in time, resulting in high self-discharge or a dead cell. Worst case, it turns into a hard short and a fire. In theory, the BMS or charger should prevent charging too fast or too cold, but who knows if an edge-case like this is actually implemented correctly on any particular battery system. Be careful charging! Alex MeVay Genasun * Blue Sky Energy * http://sunforgellc.com _______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org There are two list archives for searching. When one doesn't work, try the other: https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out or update participant bios: http://www.members.re-wrenches.org