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Alternators

Marine Alternators & Charging System Parts

Shop Marine Alternators & Charging Components

Find marine alternators, high-output alternators, voltage regulators, pulleys, brackets, serpentine belt components, and charging-system accessories for inboard, sterndrive, and diesel engines. Search by part number, engine brand, amperage, voltage, or product type to keep your batteries charging reliably.

Shop Alternators Search Marine Alternators Voltage Regulators
Fitment Reminder

Confirm part number, engine model, mounting style, pulley type, amperage, and voltage before ordering.

Shop High-Output Alternators

Always verify alternator fitment using your engine serial number, OEM part number, pulley alignment, and charging-system requirements.

Volvo Penta Yanmar Mercury MerCruiser Sierra 12 Volt 75 Amp Serpentine Pulleys

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Shop by Charging Category

Choose the alternator or charging-system component that matches your engine, belt drive, and onboard electrical load.

All Alternators Marine Alternators High-Output Alternators Voltage Regulators Alternator Pulleys Mounting Brackets Charging Accessories

Why It Matters

Alternators Keep Your Boat's Electrical System Supplied

A marine alternator charges batteries and helps support electrical loads while the engine is running. Weak output, bearing noise, belt issues, or regulator problems can leave batteries undercharged.

Marine-grade alternators and charging parts are built for engine-room heat, vibration, corrosion exposure, and the electrical demands of modern onboard systems.

AMP

Match Output and Voltage

Confirm amperage and voltage before replacing an alternator. Common marine systems use 12 volt charging, but output ratings vary by engine and battery bank.

FIT

Check Mounting and Pulley Style

Alternators can differ by case size, mounting ears, pulley diameter, belt type, serpentine setup, wiring plug, and rotation requirements.

CHG

Inspect the Full Charging System

Belts, pulleys, regulators, wiring, grounds, and batteries all affect charging performance. A failed part can point to a larger system issue.

Parts Desk Guidance

Alternator Assembly or Related Component?

If the alternator has failed mechanically or electrically, a complete replacement may be needed. If the issue is output control, belt alignment, noise, or mounting, a regulator, pulley, bracket, belt, or accessory part may solve the repair.

Choose an alternator For failed charging output, worn bearings, damaged housings, or a direct OEM replacement by part number.
Choose a high-output alternator When the boat has larger battery banks, added electronics, refrigeration, inverter loads, or upgraded charging needs.
Choose a voltage regulator When output control or charging behavior is the issue and the alternator itself is still serviceable.
Choose pulleys, brackets, or hardware For belt alignment, mounting repairs, serpentine conversions, or charging-system installation work.

Common Questions

Marine Alternator Buying Help

How do I find the correct marine alternator?

Start with the OEM part number, engine serial number, engine model, alternator label, mounting pattern, pulley style, voltage, and amperage rating. Exact part-number confirmation is the safest path.

Can I replace a marine alternator with an automotive alternator?

No. Marine alternators are designed for the engine-room environment and must meet ignition-protection and corrosion-resistance expectations for marine use. Use a marine-grade replacement.

When should I consider a high-output alternator?

Consider high-output charging when your boat has larger battery banks, heavy electronics, inverter loads, refrigeration, or frequent low-speed charging needs that exceed the original alternator's capability.

What else should I inspect when replacing an alternator?

Inspect belts, pulleys, brackets, wiring, grounds, battery condition, fuses, and regulators. Charging problems can come from more than the alternator itself.

Ready to Find Your Part?

Search Marine Alternators, Regulators & Charging Parts

Use the collection page or search by brand, part number, amperage, voltage, pulley type, or charging-system component.

Shop All Alternators Volvo Penta Yanmar Sierra

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Seachoice 11280 30 Amp Marine Rated Battery Fuse

Seachoice 11280 30 Amp Marine Rated Battery Fuse

$31.31 - $31.31
$31.31
$31.31 - $31.31
$31.31
In stock

These marine rated fuses are suitable for main and auxiliary circuit protection (alternator outputs, starter motor inputs and accessories) in deman...

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$31.31 - $31.31
$31.31
$31.31 - $31.31
$31.31
Battery Mate Battery Isolator, 160A, 2 Bank

Battery Mate Battery Isolator, 160A, 2 Bank

$705.79 - $705.79
$705.79
$705.79 - $705.79
$705.79
In stock

The Battery Mate is the ultimate solution for charging several batteries simultaneously and is compatible with any type of alternator/battery charg...

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$705.79 - $705.79
$705.79
$705.79 - $705.79
$705.79

ProMariner - Battery Isolator - 21302

$0.00 - $0.00
$0.00
$642.58
$642.58 - $642.58
$642.58
In stock

The ProMariner 2-130-2 Multi-Battery Isolator is a solid-state DC charging isolator for marine electrical systems with two alternator inputs and tw...

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$0.00 - $0.00
$0.00
$642.58
$642.58 - $642.58
$642.58
ProMariner Battery Isolator

ProMariner Battery Isolator

$435.20 - $435.20
$435.20
$435.20 - $435.20
$435.20
In stock

Rated for 130 amps maximum alternator. Operates on 6, 12, 24 & 32 volt negative ground systems. Electrical current able to flow from DC source ...

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$435.20 - $435.20
$435.20
$435.20 - $435.20
$435.20

Alternator 75A 12V Serpentine SIE-18-5882

$605.32 - $605.32
$605.32
$605.32
$605.32 - $605.32
$605.32
Only 1 left!

High-output 75-amp 12-volt alternator with serpentine belt drive for reliable marine electrical charging performance. Part Number: SIE-18-5882 Th...

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$605.32 - $605.32
$605.32
$605.32
$605.32 - $605.32
$605.32

Sierra Marine Alternator - High-Output Charging System

$255.00 - $255.00
$255.00
$255.00
$255.00 - $255.00
$255.00
Only 1 left!

Sierra marine alternator engineered for reliable electrical charging system performance. This high-quality alternator ensures consistent power gene...

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$255.00 - $255.00
$255.00
$255.00
$255.00 - $255.00
$255.00

Volvo Penta Alternator 3840181

$0.00 - $0.00
$0.00
$1,365.00
$1,365.00 - $1,365.00
$1,365.00
Only 1 left!

OEM Volvo Penta alternator assembly for reliable electrical charging performance in marine applications. Part Number: 3840181 This genuine Volvo ...

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$0.00 - $0.00
$0.00
$1,365.00
$1,365.00 - $1,365.00
$1,365.00

Mercury Alternator 8M0064021 - OEM Marine Charging System

$1,221.74 - $1,221.74
$1,221.74
$1,221.74
$1,221.74 - $1,221.74
$1,221.74
Only 1 left!

OEM Mercury alternator assembly for reliable electrical charging performance in marine applications. Part Number: 8M0064021 This genuine Mercury ...

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$1,221.74 - $1,221.74
$1,221.74
$1,221.74
$1,221.74 - $1,221.74
$1,221.74

AC Delco Marine Alternator - High-Output Charging System

$261.00 - $261.00
$261.00
$261.00
$261.00 - $261.00
$261.00
Only 1 left!

AC Delco marine alternator engineered for reliable battery charging and electrical system power in demanding marine environments. This high-output ...

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$261.00 - $261.00
$261.00
$261.00
$261.00 - $261.00
$261.00