Recharges all M18™, M14™ and M12™ REDLITHIUM™ battery packs Recharges in sequence - first in, first to charge - resulting in less time needed to manage charging cycles M12™ REDLITHIUM™ 2.0 Ah / 3.0 Ah / 4.0 Ah / 6.0 Ah battery packs recharge in 26 min / 50 min / 52 min / 95 min or less M18™ REDLITHIUM™ 2.0 Ah / 4.0 Ah / 5.0 Ah battery packs recharge in 26 min / 52 min / 59 min or less. Milwaukee M12 / M18 Fast Battery Charger