SPI Series Schumacher Battery Chargers: FASTER, SMARTER, SAFER ECO-FRIENDLY Patented Speed Charge Technology ensures that the battery is charged as fast and safely as possible – up to 3 times faster than traditional chargers. Designed to charge most types of batteries (AGM, Gel, Calcium/Wet, Stop/Start. The SPI3 is also compatible with lithium-ion batteries. The range features a digital display with scrolling multilingual instructions (except SPI1 SPI2) insulated clamps and eyelet accessories (except SPI15 and SPI1224V), a hook attachment and protection bumpers. FEATURES: Reverse polarity protection, thermal runaway protection and automatic shut-off are included as standard.The SPI will charge batteries with voltage as low as 0.5V. In comparison, most chargers from the competition .