These heavy duty isolators allow charging multiple batteries automatically from one or two alternators, and prevent discharge or ‘dumping” of one battery into another. Each battery is charged according to its need without overcharging. Rated for 12-48 volt negative ground DC systems. Feature conservatively rated diodes and a rustproof anodized aluminum heat sink case. Models are available for 70, 120 and 165 amp alternators.


  • Heavy duty construction
  • Rated for systems up to 48 volts DC, negative ground
  • Rust-proof anodized aluminum case
  • Stainless steel mounting hardware provided
  • Protective covers provided for terminals
SKU: N/A Category:


ModelAlternatorBatteryMax AmperageWeightDimensions
SourcesBankInput CapacityLbsKgLWH
1-2-70127020. in
8.311.47.9 cm
1-3-70137020. in
8.311.47.9 cm
2-3-70237041. in
16.511.47.9  cm
1-2-1201212031. in
16.511.48.0 cm
1-3-1201312031. in
16.511.4  8.0  cm
2-3-1202312052.312.54.53.1 in
30.511.47.9 cm
1-3-1651316552.394.53.1 in
22.9 11.4 8.0  cm

Application Note: Battery Isolators may also be used to facilitate N+1 parallel/redundant operation of power supplies. Contact factory.

Performance Specifications

Operating temperature: -40 to +80° C

Duty cycle: Continuous rating to 50° C; Derate linearly to 70% @ 80° C

Temp. rise: 95° C at full rated current (mount vertically for optimum cooling)

Voltage drop: 0.7V @ 50% load; 0.9V @ full load

Note: These battery isolators are not compatible with self exciting alternators. Please consult the manufacturer of your alternator if you are unsure of your configuration.