Description
THE HIGHEST POWER OUTPUT ALTERNATOR IN ITS SIZE/CLASS
- Engineered for High Energy Production.
- Suitable for Marine, RV, Military, and Commercial applications.
- Rapidly charges large battery banks.
- Coolest operating temperatures for increased performance. Runs 8 - 20% cooler than incumbent alternators due to:
- Heat shedding coatings
- Rectifier located on housing exterior
- Dual cooling fans
- OEM Components
- Optimized for performance at idle speeds.
- Reduces need for generator by creating additional power with your engine.
- Unleash peak performance with E-Coat/Cerakote. Our advanced coating absorbs less heat, keeping the A275L cooler. This translates to more amperage for sustained periods.
- For maximum performance or lithium battery charging, use an ARCO Zeus Bluetooth alternator regulator.
- SAE J1171 Certified.
- Proudly made in the U.S.A.
Click here to optimize your alternator's output with the ARCO Zeus Bluetooth alternator regulator.
Technical Specifications
Voltage | 12V |
Field Type | P |
Rotor Poles | 16 |
Stator Size | 138mm |
Frame Size | Large |
Weight | 14.9 lbs / 6.7 kg |
Regulation | Internal/External (IE) or External Only (EX) |
Output Voltage | 14.1V (default) |
Finish | (Black) Cerakote or E-coating |
Cut-In RPM | 1,061 Alternator RPM |
Maximum Alt RPM | 19,000 |
Battery Post | M8 Thread Post, Side Mount |
Standard Pulley | 49K6 (6-groove, 49mm) |
Pulley Mount | 17mm diameter shaft, 25mm long, threaded M17 x 1.5 |
Pulley Hardware | M17 x 1.5 x 24mm nut, w/ 18mm ID x 29mm OD washer (Included) |
Diodes | 6 positive, 6 negative, 50A Rated, Avalanche |
Max Output (Cold, 9,000 RPM) | 311 Amps |
Sustained Cruising Output (Hot, 6,000 RPM) |
227 Amps |
Sustained Idle Output (Hot, 3,000 RPM) |
198 Amps |
Max Continuous Operating Temperature | 110°C / 230°F |
Mounting Options & Applications
Mounting | ARCO Part Number | Application |
1-2” Single Foot | A275L-12-SF12-EX-49K6 A275L-12-SF12-IE-49K6 |
Replaces most domestic styles using a single 1or 2”mounting foot (e.g., Motorola, Prestolite). |
3.15” J180 Saddle | A275L-12-DF315-EX-49K6 A275L-12-DF315-IE-49K6 |
Replaces most small case styles using a 3.15” J180 saddle style mount (e.g., Hitachi, Lucas, Mitsubishi) Most Yanmars. |
4” J180 Saddle | A275L-12-DF4-EX-49K6 A275L-12-DF4-IE-49K6 |
Replaces most Volvo Penta alternators using a 4” J180 saddle style mount |
Vortec/GM | A275L-12-VT-EX-49K6 A275L-12-VT-IE-49K6 |
Replaces Mando type alternators using Vortec/ GM pad mounting feet (Found on many Mercruiser and Volvo Penta 3.0GLM, 3.0GLP, 4.3GXi, 5.7GiL, 5.7GXiL Marine Engines.) (GM Blocks ) |
N62 | A275L-12-N62-EX-49K6 A275L-12-N62-IE-49K6 |
Replaces most Mercedes and BMW alternators Mercedes Sprinter 1999-2006 alternators Mercedes Sprinter Factory dual alternator 2007-Up Replacement |
Transit | A275L-12-TR-EX-49K6 A275L-12-TR-IE-49K6 |
Replaces Ford Transit alternators 3.5L & 3.7L Gas engines 2015-2022 |
N62 (Clutch Pulley) | A275L-12-N62-EX-50K6CP A275L-12-N62-IE-50K6CP |
Mercedes Sprinter 1999-2006 alternators Mercedes Sprinter Factory dual alternator 2007-Up Replacement Replaces Roadtrek Mercedes Dual alternator |
Transparency - How we test for output
To measure sustained output, the alternator is run at 3,000 RPMs for 60 minutes with a plexiglass shield covering the units. Testing shows that after 60 minutes in these conditions, alternators reach their maximum operating temperature, or the conditions under which the unit will produce the least output.
It is under these harsh conditions where we measure the “hot” output of the units at various RPMs. The complete power curve is shown above.
Note: The “hot” conditions are much less favorable than the conditions typically used in the industry. The temperature of the stator during our “hot” test was 305 °F. Incumbents measure the power curve at an ambient temperature of 140 °F. “Cold” testing was done at 71° F.
Cross Reference
ARCO Zeus A275L | APS | Mechman | Balmar |
A275L-12-DF315-EX-49K6 | 360HSB1H652S9E4 | - | - |
A275L-12-DF315-IE-49K6 | - | - | XT-DF-250-K6 |
A275L-12-DF4-EX-49K6 | 42I-270-14JEXT/STA | - | - |
A275L-12-DF4-IE-49K6 | 360HVOPRIG1H852S9E2 | XT-DF4-250-K6 | |
A275L-12-N62-EX-49K6 | 360HN621H652S9CE4 | - | - |
A275L-12-N62-IE-49K6 | - | - | XT-MS-250-K6 |
A275L-12-SF12-EX-49K6 | - | - | - |
A275L-12-SF12-IE-49K6 | - | - | XT-SF-250-K6 |
A275L-12-TR-EX-49K6 | - | - | - |
A275L-12-TR-IE-49K6 | - | 11630320 | XT-EB-250-K4 |
A275L-12-VT-EX-49K6 | - | - | - |
A275L-12-VT-IE-49K6 | 360H15RVC1H652S9C | M8206250 | XT-VT-250-K6 |
Support & Downloads
ARCO Zeus A275 Alternator DatasheetEstimate shipping
Refund Policy
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 the merchandise is missing parts or is not in new condition.
- Returns accepted for 30 days
- Customer is responsible for return shipping. If you request The Yacht Rigger to provide a shipping tag, the shipping cost will be deducted from your refund.
- A 3% restocking fee will apply.
- No returns on final sale items.
If your return request is accepted, we’ll send you a return shipping label and instructions on how and where to send your package. Items sent back to us without first requesting a return will not be accepted.
To start a return, please contact us at sales@theyachtrigger.com.
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 or email us at sales@theyachtrigger.com.
Exceptions / Non-Returnable Items
Certain types of items cannot be returned, such as custom products and special orders. We also do not accept returns for hazardous materials, flammable liquids, or gases. Please get in touch if you have questions or concerns about your specific item. 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.
Arco A 275 alternator is almost a perfect fit on a yanmar 4jh3e. Installed with balmar pulley kit . Easy install and fast charging .n more belt dust covering everything.
Installed A275L on a Yanmar 4JH3E without problems. The B+ post is removable to allow for fit under the heat exchanger. I already had a Serpentine kit (J10).
I'm using our existing Balmar regulator, hope to upgrade later to Zues reg later.
Using Balmar's belt manager I crimp it to ~150A, steady around 1250 engine RPM, 300 Alt.
Had a great experience ordering from The Yacht Rigger, they were able to accommodate to my travel schedule.
Great customer service!
That's wonderful to hear! Thank you so much for the 5 star review! Leaving a positive review like this helps others know what to expect. Fair winds and following seas.