This onboard marine battery charger from Schumacher is durable and provides efficient sequential charging. It charges two batteries alternately, with the first for 15 minutes and then the second, ensuring that devices are always ready for use without long wait times. It automatically detects connected batteries and uses advanced multi-stage charging technology to extend battery health and lifespan. The charger is compatible with various batteries including Standard, AGM, Gel, and Deep Cycle. It has an IP65 protection rating, making it water resistant and suitable for marine, humid, or dusty environments. The charger can be easily attached vertically or horizontally using its four mounting slots.