Kussmaul Auto Isolator Cat. No. K-091-139-

The Auto Isolator I detects when a vehicles alternator is charging the battery and then closes a solenoid operated switch to additionally charge an auxiliary battery. When the engine is stopped, the solenoid opens to isolate the batteries. Upon "cranking" the engine with a charged auxiliary battery, the solenoid is energized to parallel the batteries and provide a starting boost. If the auxiliary battery is low, the batteries are not paralleled. Since the auxiliary battery is charged through a solenoid-operated switch rather than an isolation diode, the auxiliary battery is fully charged. The .7 volt diode drop is eliminated, as is the power dissipation in the diode. The system therefore is more efficient. The starting boost provided by the parallel batteries is especially useful in cold weather or when the main battery is low. Replaces Diode Isolator in 2 Battery System High Efficiency, No Diode Drop Automatically Maintains Charge in Auxiliary Battery Provides Boost on Starting by Paralleling Batteries Specifications: Controller, Model # 091-139-CONT12: Volts to parallel: 13.0 Vdc, field adjustable Battery load: .000125 amps Output current: 3 amps max. Weight: .5 lbs   Solenoid, Model # 091-139-SOL12HO: Volts: 12 Vdc Coil current: .45 amps Contact rating: 200 amps cont. / 600 amps surge Weight: 2.0 lbs      Datasheet.pdf (484 Kb) Instruction Manual.pdf (122 Kb) Model: Auto Isolator I, Model 091-139-2-12 : $245.60 Auto Isolator 3, 091-208-3-12 : $358.30 Battery Isolator 1 Controller 091-139-CONT-12 : $123.60 Battery Isolator 1 & 3 Solenoid 091-139-SOL-12HO : $114.50 Battery Isolator 3 Controller 091-208-CONT-12 : $118.50