The Mastervolt BI1202-S BI Series Battery Isolator is a compact, fully solid-state solution that divides your charge current with minimal energy loss. Designed for dual-battery installations on 12 or 24 V systems, it keeps two battery banks charged independently while sharing the same charging source. The BI1202-S integrates the Charge Mate feature for connecting and/or disconnecting two batteries, and Battery Watch for monitoring battery health (also usable as a main switch).
Key advantages
-
Two battery outlets for independent charging paths
-
Max output from the charger up to 80 A and from the alternator up to 120 A
-
Diode-based technology with voltage drop compensation (0.6 V) to maximize charging efficiency
-
Automatic voltage drop compensation supported by Mastervolt Mass chargers and Alpha Pro regulators
-
Solid-state construction, compact design, and corrosion-proof housing with aluminum heat sinks
-
End plates with connection lugs and bolt connections with nuts and locking rings for easy installation
-
Completely encapsulated electronics and molded diode splitters for durability
Specifications at a glance
-
Number of battery outlets: 2
-
Dimensions (HxWxD): 8.1 x 5.5 x 3.1 inches
-
Weight: 2.6 kg
-
Max output charger: 80 A
-
Max output alternator: 120 A
-
Compensation diode: Yes
Designed for boats, caravans, and any multi-battery electrical system, the BI1202-S ensures reliable, efficient charging while protecting each battery bank. If you’re looking to simplify dual-battery charging with a robust, low-maintenance isolator, this Mastervolt model delivers.
| General specifications |
| Number of battery outlets |
2 |
| Dimensions, hxwxd |
8.1 x 5.5 x 3.1 inch |
| Weight |
2.6 |
| Technical specifications |
| Max. output battery charger |
80 A |
| Max. output alternator |
120 A |
| Compensation diode |
Yes |
