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    • Mastervolt Alpha Pro III 45513000
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    Mastervolt Alpha Pro III [45513000]

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    Sale Price $376.99 Regular Price $673.99
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    Alpha Pro III

    Advanced 3-step charge regulator for standard and high performance alternators

    The propulsion engine of your boat or vehicles may be used to quickly charge your service batteries, either while cruising or taking a break. The advanced and powerful Alpha Pro III ensures fast and safe charging, protecting both the engine and the batteries. Building on 10 years of experience, the Alpha Pro III features a modernized look, higher power and improved ease of use.

    The Alpha Pro III measures the temperature and the voltage of your batteries to prevent overcharging, keeping them in perfect condition. It also monitors the engine load, thus reducing sound variations, wear and tear. The smart ‘keep alive’ feature solves a common problem causing unreliable tachometer readings. Via MasterBus, it communicates RPM, alternator status and charge status to create intelligent power systems. 

    Pull the max out of your alternator

    The alternator that comes with the engine is not optimally suited for charging service batteries. Designed for low cost and short charge cycles, it charges at a slow pace and is easily overheated. Replacing the standard regulator* with the Alpha Pro III optimizes this charging process, protects against overheating and overcharging and extends the lifetime of your batteries. 

    (* not allowed on Euro 5/6 engines)

    Super charge your system

    For superfast charging at low RPM, Mastervolt recommends to combine the Alpha Pro III with a high performance alternator such as the reputable Alpha series. With 20 amps of field current capability, the Alpha Pro is the only 3-step regulator in the market capable of controlling alternators with outputs up to 400 A!

    Alpha Pro III: Fast charging, anytime, anywhere. 

    Features:

    • Transforms every alternator into a full temperature controlled 3-step charger.
    • Reduces run time, saves fuel, reduces noise and emissions.
    • Protects from overcharging and extends battery life.
    • Balances engine load, reducing RPM variations.
    • Compatible with standard and high performance alternators, incl. 200 A 400 A models.
    • Integrated ‘keep alive’ feature for reliable tachometer readings.
    • Suitable for every battery type, including Lithium Ion.
    • Suitable for 12 V and 24 V system voltages.
    • Masterbus compatible: simplifies wiring, saves space and weight, and creates optimal cooperation between Mastervolt products.

    Applications:

    Applications range from improving the performance of a standard alternator in a vehicle or boat, to generator replacement, when combined with a high performance alternator. 

    WarningWARNING: This product can expose you to chemicals including di(2-ethylhexyl)phthalate (dehp) which is known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.


    Owner's Manual (pdf)
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    User Manual Download
    Specification Sheet Download
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    Service & Support

    Warranty

    This product is backed by a 12-month limited warranty, covering defects in materials and workmanship under normal use.

    Technical Assistance

    Our dedicated support team is available to assist with product setup, operation guidance, and troubleshooting. Contact us via email or phone for prompt service.

    Documentation & Downloads

    Access essential resources including the user manual, technical specifications, and safety instructions in our online support center.

    Replacement Parts & Accessories

    We offer a full range of genuine replacement parts, including batteries, chargers, and compatible accessories to ensure long-term performance.

    Training & Tutorials

    Browse our library of how-to videos and maintenance tips to get the most out of your cordless drill.

    FAQs

    Find quick answers to common questions

    Product & Usage

    1. Is your gear authentic and warranty-backed?

    Yes — we are an authorized US dealer for 300+ marine electronics brands. Every order ships with the manufacturer’s full warranty.

    2. Are these products beginner-friendly?

    Yes. Our products are designed for both seasoned boaters and first-time owners. Each unit ships with a manufacturer manual, and we’re happy to answer setup questions over email.

    3. Are these products built for marine conditions?

    Yes. Marine electronics are engineered for saltwater spray, vibration, and weather. Check the product specs for IPX waterproof rating and saltwater certifications.

    Maintenance & Accessories

    1. What maintenance does marine electronics require?

    Rinse with fresh water after saltwater exposure, store in a dry place, and follow your manufacturer’s cleaning and storage instructions.

    2. Can I buy replacement parts and accessories separately?

    Yes — we carry replacement parts, mounts, transducers, cables, and accessories for the brands we stock.

    3. Do you provide product manuals or installation guides?

    Every product ships with the original manufacturer’s manual. Digital copies and detailed installation guides are typically available on the brand’s website.

    Warranty & Guarantee

    1. Does my purchase include a warranty?

    Yes — every order includes the full manufacturer warranty. Coverage length varies by brand (typically 1–3 years for Garmin, Lowrance, Raymarine, Simrad, Humminbird, Furuno, and others).

    2. How do I register for warranty coverage?

    Register directly with the manufacturer using your unit’s serial number. Manufacturer registration is the fastest path to warranty support if you ever need it.

    3. What does the manufacturer warranty cover?

    Defects in materials and workmanship under normal use. Damage from impact, improper installation, or saltwater corrosion (without protection) may be excluded. Check brand-specific terms in your unit’s documentation.

    4. Can I extend the warranty?

    Some manufacturers offer extended-coverage programs through their registration portals. We don’t sell third-party warranty programs.

    Purchasing & Support

    1. How fast does my order ship?

    Orders placed before 4pm EST Monday–Friday ship the same business day via UPS from our NJ or FL warehouses. Continental US delivery typically takes 3–7 business days for Economy.

    2. Do you offer bulk or fleet pricing?

    Yes — we offer volume pricing for fleet operators, marinas, dealers, and commercial customers. Email support@marineelectronicsdepot.com with your needs.

    3. How can I contact support?

    Email support@marineelectronicsdepot.com or call during business hours (Mon–Fri 9am–5pm ET). We’re happy to help with pre-purchase questions, order status, or post-sale support.

    Can’t find your answer?

    Feel free to reach out to us!

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