A battery cell charging system, including a charger and a controller, for low-temperature (below about zero degrees Celsius) charging a lithium ion battery cell, the battery cell charging system includes: a circuit for charging the battery cell using an adjustable voltage charging-profile to apply a charging voltage and a charging current to the battery cell wherein the adjustable voltage charging-profile having: a non-low-temperature charging stage for charging the battery cell using a charging profile adapted for battery cell temperatures above about zero degrees Celsius; and a low-temperature charging stage with a variable low-temperature stage charging current that decreases responsive to a battery cell temperature falling below zero degrees Celsius.