The Sealey SPI3S is a fully automatic microprocessor controlled battery charger and maintainer that benefits from patented speed charge technology, which actively monitors the charge acceptance and constantly modifies the charge output. This model charges the battery up to 3 times faster than conventional chargers without damaging the battery and its heavy-duty case, LED status lights, digital display screen, offering step by step instructions. This unit can charge conventional lead acid, calcium, AGM/GEL, leisure, stop/start batteries and is completed with reverse polarity protection, thermal runaway protection and automatic shut-off for added safety and battery reliability.