Charging lithium batteries in cold weather (below 50 deg F) can cause permanent damage to the battery? Yes, it is true. In fact, at temperatures approaching freezing, a single charge to 4.2v can actually cause complete loss of battery capacity. The damage is permanent and irreversible. For this reason, the Cellpro 4s charger monitors ambient temperature and reduces the full charge voltage to 4.1v per cell below 50 deg F, preventing damage to the batteries.