Alternator, XT series, 250A, 12V, single foot 1-2"

The Balmar XT-SF-250-K6 alternator from the XT series delivers up to 250A at 12V and uses single-foot/spindle mounting (1-2") – a design often found on Volvo and Delco-style engines. It is aimed at owners of large yachts, motorboats, or RVs whose electrical systems, with extensive lithium battery banks, air conditioning, or multiple consumers running simultaneously, would overwhelm a classic alternator.

Advantages

• 250A charging power at 12V for fast recharging of large battery banks
• Up to 186A charging current already at idle speed – many times more than classic 30-40A alternators at idle
• Patented Smart Ready® technology with internal regulator as basic protection
• Dual fan cooling and high airflow for reliable continuous operation
• Explicitly suitable for large lithium battery banks
• Braided 96-groove winding design instead of classic 36-groove S-winding: more efficiency and 5-10°C cooler operation than the predecessor AT series
• Certified according to USCG Title 33, ISO 8846, and SAE J1171

Technical Data & Compatibility

• Power: 250A / 12V
• Mounting type: Single-foot/spindle mounting 1-2" (SF) – fastened via a single foot or spindle bolt, typical for Volvo and Delco-style alternator brackets
• 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 single V-belt is not sufficient for this power class – an AltMount© pulley conversion kit is necessary without an existing dual V-belt or serpentine belt
• For non-adaptive speed display, the Balmar 15-TSS tachometer signal stabilizer may be required
• For Yanmar engines with common rail technology and newer Volvo engines, the 61-0050 (K6) pulley is needed

Does single-foot mounting fit my engine?

The 1-2" single-foot/spindle mounting is standard on many Volvo Penta and Delco-style engines. Before purchasing, compare the foot mount on your engine with the dual-foot variant (XT-DF-250-K6) – if in doubt, our support team can help you make the right choice.

Single or as a set?

The "single" variant (SKU 752125004) includes only the alternator and is suitable if a suitable multi-stage regulator is already present. The "set" (SKU 752125005) additionally includes the MC-618 multi-stage regulator with temperature sensors and is particularly recommended for new installations in this high power class, as precise temperature monitoring protects batteries and the alternator.

Area of Application

Suitable for large sailing and motor yachts as well as RVs with high power demands, for lithium conversions, and for boat owners who frequently use their engine at idle for charging.

Not sure whether single-foot or dual-foot mounting fits your engine? Contact our support team – we'll clarify it with you.