The Schumacher Electric 6V/12V 125A ProSeries Battery Charger/Engine Starter, No. DSR145, is designed to instantly start a vehicle with a dead battery. The unit features 15<>40A boost mode for discharged batteries, 15<>40A service mode to maintain stable voltage during service, 6A charge mode to precisely charge all types of lead acid batteries including AGM and gel, recovery mode to recover a sulfated 12V battery, and a built-in alternator tester. With push-to-start charging, the user can manually charge a battery with a voltage reading as low as zero. The DSR145 also offers a digital display for real-time feedback and built-in safety protections including reverse polarity, short circuit, and overheat.