The ML-ACR 12V Automatic Charging Relay with Manual Control is a 500 Amp magnetic latching (bi-stable) relay which automatically combines batteries during charging and isolates batteries when discharging and when starting the engine. The manual control switch provides an added level of safety allowing control with or without power, and offering LOCK OFF capability for servicing. The relay allows paralleling of battery banks for emergency starting. It has a LED output to remotely indicate when batteries are combined, isolated, in voltage lockout, or in Start or Engine isolation (requires optional LED). Includes ML-Series Remote Control Contura Switch.