Alternator for Volvo D1 / D2, XT series, 250A, 12V, double base 4"

The Balmar XT-DF4-250-K6 alternator from the XT-Series is specially designed for Volvo D1 and D2 engines, delivering up to 250A at 12V via a dual-foot mounting with a 4" foot spacing. It is the ideal choice for sailboats and motorboats with Volvo D1/D2 drives and an onboard electrical system that is pushed to its limits by lithium battery banks, refrigerators, or additional electronics with the factory-installed alternator.

Advantages

• 250A charging power at 12V, specifically tuned for Volvo D1/D2 engines
• Up to 186A charging current already at idle speed – significantly more than the 30-40A of classic alternators at idle
• Patented Smart Ready® technology with internal regulator as a fallback safeguard
• Dual-fan cooling with high airflow for stable temperatures during continuous operation
• Suitable for lithium battery banks
• Braided 96-slot winding design instead of classic 36-slot S-winding: higher efficiency and 5-10°C cooler operation than the AT-Series
• Certified according to USCG Title 33, ISO 8846, and SAE J1171

Technical Data & Compatibility

• Power: 250A / 12V
• Mounting type: Dual-foot mounting 4" (DF4) – specifically for Volvo D1 and D2 engines with corresponding foot spacing, not compatible with the standard 3.15" dual-foot mount of other engines
• Pulley: K6-Serpentine (6-groove, approx. 69mm / 2.6-2.7" diameter)
• Dimensions: Housing diameter approx. 142-145mm, total height depending on foot variant approx. 198-244mm
• A simple V-belt is not sufficient for this power class – if a double V-belt or serpentine belt is not yet present on the D1/D2, an AltMount© pulley conversion kit is required
• For non-adaptive RPM display, the Balmar 15-TSS tachometer signal stabilizer may be required
• Since Volvo D1/D2 are among the newer Volvo engines, the 61-0050 (K6) pulley is often required – please check before installation

Does this alternator fit my Volvo D1 or D2?

The XT-DF4-250-K6 was specifically designed for the 4" dual-foot mount of Volvo D1 and D2 engines and thus differs from the standard dual-foot variants (3.15") for other engines. Please check your engine type and foot spacing before ordering – if in doubt, our support team will be happy to help you.

Individually or as a Set?

The "individual" variant (SKU 752125018) includes only the alternator, ideal for a pure replacement with an already existing suitable regulator. The "set" (SKU 752125019) additionally includes the MC-618 multi-stage regulator including temperature sensors and is the recommended solution for a complete new installation on the Volvo D1/D2, especially for planned lithium conversion.

Application Area

Designed for sailboats and motorboats with Volvo D1 or D2 engines and larger onboard electrical systems, for conversion to lithium batteries, and for owners who regularly use their engine at idle for charging, for example in anchorages.

Do you have a Volvo D1 or D2 and are unsure if the 4" dual-foot mount is suitable for your engine? Contact our support team – we will advise you on the appropriate version and the necessary accessories.