The A18J/A20R features a 2-year warranty. These Chargers are completely automatic and are designed for continuous operation on unloaded Engine Starting Batteries. They are intended for mounting near the Engine Generator Set to be permanently connected to the Battery and AC lines. They are built for Flooded Lead-Acid Batteries and are not suitable to charge Sealed Valve-Regulated Batteries since these require a filtered charger (please refer to our models A40F/A46F for this type of application).The A18J and A20R will automatically sense the Battery condition and will shutdown to milliampere currents once the Battery becomes fully charged. These models, in their simplicity were not designed to carry any DC loads, they are typically used in applications where a small capacity Battery Charger is required to maintain and recharge a single Battery Bank.