An intelligent 4-stage maintenance charger for 6 or 12 volt lead-acid batteries. Maintains and extends battery life by constantly monitoring and correctly charging the battery indefinitely across four stages: pre-charge, constant current, constant voltage and float charge. Select from four charging modes, including: 6V/1A (slow), 12V/1A (slow), 12V/4A (fast), and 12V/4A (low temperature). The LCD interface clearly displays modes and measurement detections to ensure ease of operation. Safety features include short circuit and reverse polarity protection, wrong battery prompt, over temperature protection and power down memory. Numerous charging options make this a great choice for many vehicle, home and industrial battery charging requirements. The handy retractable hook means you can hang it where you need it.