1-2-120 Battery IsolatorThis heavy-duty isolator allows multiple batteries to charge automatically from one or two alternators and prevents the discharge or dumping of one battery into another. Each battery is charged according to its need without overcharging and is rated for 12-, 24-, or 36-volt, negative ground DC systems. This model is a 120-amp alternator.Features:Conservatively rated diodes and a rustproof anodized aluminum heat sink caseHeavy duty constructionRated for systems up to 48 volts DC, negative groundRust-proof anodized aluminum caseStainless steel mounting hardware providedProtective covers provided for terminalsSpecifications:Operating Temperature: -40 to +80Duty Cycle: Continuous rating to 50 C Derate linearly to 70% @ 80 CTemp. Rise: 5 C at full rated current (mount vertically for optimum cooling)Voltage Drop: 0.7V @ 50% load, 0.9V @ full loadAlternator Sources: 1Battery Bank: 2Max. Amperage Input Capacity: 120Stud Terminal Size: 6mmDimensions (L x W x H): 6.5″ x 4.5″ x 3.1″Weight: 3 lbs.Note: These battery isolators are not compatible with self-exciting alternators. The alternator must have an external excitation lead. Please consult the manufacturer of your alternator if you are unsure of your configuration