As others have said it will not charge a fully discharged lithium battery which seems impractical given its purchase. Bought a new Lithium Dakota 12v a month ago and this charger. When the battery needed to be charged from "empty", only the power LED would light up with no indication of battery charge. I then connected a 1 amp charger which started charging immediately. After 15 minutes I plugged this charger in and it finally accepted the battery, indicated it finally charged and fully charged it. Customers who purchase this product do not need 2 different chargers to charge a new lithium battery.