This dual purpose, dual voltage charges both 12 and 16 volt batteries and maintains them. The battery type switch can be set for any Lead Acid, Sealed, Gel Cell type, Wet/Deep Cycle and ''Reactor'' batteries. The fully automatic 3-stage microprocessor controlled proportional timing, constant first stage. The 30 amp rating means the fastest charging available. Most batteries will not start or recover if they have under 9 volts. The Low Start Voltage allows you to begin charging a battery with a voltage as low as .02 of a volt. Other features include a short and reverse polarity connection shutdown, solid state LED Ammeter shows that the battery condition is charging, at 80% or READY (and no fragile moving meter parts to break). There is also a Hibernate mode that is perfect for long storage and sutomatically shuts down to zero output minimal energy consumption after 24 hours, applying a maintenance charge cycle once every thiry days.