This means that if you have 12v battery, which was drained because of leakage currents in your car to 5-6-7V, the charger will refuse to charge it, because it doesn't know whether it is heavily discharged 12V battery of fully charged 6V battery.
Their disadvantage is that if the battery is heavily discharged, the charger will refuse to charge it. They are SMPS based chargers with control electronics. Many stores sell them under different brands, including Lidl, Praktiker and etc. This is generic charger, sold under many different names.
Re: Harbor Freight car battery chargers any good?
