Ignitions and Electrical› Charging Systems

ARCO MARINE

BATTERY ISOLATOR 2 ALTERNATORS 3 BATTERIES 120 AMP MAX

$531.84

SKU: A09I BI-3203

In Stock
In Stock
Ships by Jun 8
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Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Description

The ARCO Marine BI-3203 Battery Isolator is a solid-state device designed for use with 10 to 350-amp alternators on 12, 24, or 32-volt negative ground systems. It can handle two alternators and three batteries, ensuring both are charged proportionally to their needs when the engine is running.

Fitment

Fitment Guaranteed

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Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandARCO MARINE
Part NumberA09I BI-3203

Videos

What is the Best Alternator for my Boat?

What is the Best Alternator for my Boat?
Electrical- Alternator- 3 Step Voltage Test.wmv

Electrical- Alternator- 3 Step Voltage Test.wmv
How To: Marine Electrical Seminar - Alternators - Ep 05/30

How To: Marine Electrical Seminar - Alternators - Ep 05/30

Buy with Confidence

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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