SlashGear recommends recharging Milwaukee M12 and M18 lithium-ion batteries before they run flat: full discharge may reduce capacity and lifespan, slow charging and affect battery-management systems. It also warns that low voltage could cause overheating and, in some cases, fire.
The article recommends using Milwaukee chargers, keeping batteries sheltered while charging and leaving the charger's vents unobstructed. It says to remove the battery and unplug the charger when charging is complete, rather than leaving it overnight. For storage, it advises a cool, dry place at room temperature and cleaning dirt with a dry cloth.
The article cautions that metal bridging a battery's positive and negative terminals can cause a short circuit, damage the battery and spark a fire; it recommends keeping batteries out of toolboxes.
