Description
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.
WARNING: 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)
Estimate shipping
Refund Policy
Easy Returns
We've taken out the hassle of returning an item so you can shop with confidence. If you need to return an item, we'll provide you with a pre-paid UPS return label that you can print at home. The cost for using the label will be calculated and deducted from your refund.
To start a return, please contact us at sales@theyachtrigger.com. Items sent back to us without first requesting a return will not be accepted.
30-Day Return Policy
We have a 30-day return policy, meaning you have 30 days after receiving your item to request a return or exchange.
Eligibility for Returns
To be eligible for a return, your item must be in the same condition that you received it—unworn or unused, including tags, instruction manuals, warranty cards, and in its original packaging. You’ll also need the receipt or proof of purchase.
We reserve the right to refuse returns or assess additional fees at our discretion if:
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The merchandise is missing parts
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The item is not in new condition
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The return is beyond the accepted return dates
Return Shipping & Restocking Fees
Customers are responsible for return shipping.
If you request The Yacht Rigger to provide a shipping tag, the shipping cost will be deducted from your refund. No international return shipping labels will be provided.
A 3% restocking fee will apply.
No returns on final sale items.
Damages and Warranties
Please inspect your order upon receipt and contact us immediately if the item is defective, damaged, or if you received the wrong item.
Most items we sell are covered by manufacturers' warranties. If you experience difficulty with a product, please contact the appropriate manufacturer for assistance and troubleshooting help, or email us at sales@theyachtrigger.com. If your order was received via freight truck, you must notify us within 5 days.
Exceptions / Non-Returnable Items
Certain types of items cannot be returned, such as custom products and special orders. This includes cut line, wire, rope, and similar items that are customized to length. We also do not accept returns for hazardous materials, flammable liquids, or gases. Unfortunately, we cannot accept returns on sale items or gift cards.
Exchanges
The fastest way to ensure you get what you want is to request a return of the item you have. Once the return is accepted, you can make a separate purchase for the new item to ensure it is in stock.
European Union 14-Day Cooling Off Period
If the merchandise is being shipped to the European Union, you have the right to cancel or return your order within 14 days, for any reason and without justification. As above, your item must be in the same condition that you received it—unworn or unused, with tags, instruction manuals, warranty cards, and in its original packaging. You’ll also need the receipt or proof of purchase.
Refunds
We will notify you once we’ve received and inspected your return and inform you if the refund was approved. When processing a refund, no additional transaction fee is incurred; however, the original credit card transaction fee is not refunded.
If approved, you’ll automatically be refunded to your original payment method within 10 business days. Please allow some time for your bank or credit card company to process and post the refund. If more than 15 business days have passed since we’ve approved your return, please contact us at sales@theyachtrigger.com.
Return Policy Abuse
We reserve the right to refuse service to anyone suspected of abusing any policy of The Yacht Rigger.





