Ignitions and Electrical› Charging Systems
ARCO MARINE
BATTERY ISOLATOR 120 AMP MAX INBOARD AND OUTBOARDREPLACES SIERRA 186851
SKU: A09I BI-1203
Moderate — 2–4 hours
Description
MIA's Description
As a solid-state device, it allows electrical current to flow in only one direction. This prevents a higher-charged battery from discharging into a lower-charged one, ensuring both batteries are charged automatically and proportionally when the engine is running.
Fitment
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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
| Brand | ARCO MARINE |
| Part Number | A09I BI-1203 |
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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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