Alternator, XT series, 170A, 12V, double base 3.15″

The Balmar XT-DF-170-K6 alternator from the XT series delivers 170A at 12V and features a dual-foot/saddle mount (3.15") – the classic design for many Yanmar and Volvo engines with saddle foot mounts. It is aimed at owners of yachts, sailboats, motorboats, and RVs whose onboard electrical systems are pushed to their limits by large battery banks, refrigerators, anchor winches, or lithium storage, exceeding the capacity of classic 30-40A alternators. Core benefit: significantly more charging power in shorter engine run times, even at idle speed.

Advantages

• 170A charging power at 12V, designed for demanding onboard electrical systems
• Up to 128A even at idle speed – ideal for long anchoring periods with the engine running
• Patented Smart Ready® technology with internal regulator as basic protection/fallback
• Dual fan cooling and high-airflow casing for reliable continuous operation
• Explicitly suitable for lithium battery banks
• Modern braided 96-slot winding design instead of classic 36-slot S-winding: more efficiency, 5-10°C cooler operating temperature than previous AT-Series models
• Certified according to USCG Title 33, ISO 8846, and SAE J1171

Technical Data & Compatibility

• Power: 170A / 12V, Small-Case housing
• Mounting type: Dual-foot / Saddle mount 3.15" (DF) – the alternator is bolted to the engine via two mounting points, typical for many Yanmar and Volvo engines with factory saddle mounts
• Pulley: K6-Serpentine (6-groove, approx. 69mm / 2.6-2.7" diameter)
• Dimensions: Housing diameter approx. 134mm, total height approx. 188mm, length (Bolt-to-Bolt) approx. 124mm
• Important: For this power class, a simple single V-belt is not sufficient – if a dual V-belt or serpentine belt is not already present on the engine, an additional AltMount© pulley conversion kit will be required
• For non-adaptive tachometer displays, a tachometer signal stabilizer (Balmar 15-TSS) may be necessary
• For Yanmar engines with common rail technology and newer Volvo engines, pulley 61-0050 (K6) is required; for Yanmar 3YM engines, the XT-DF-170-XX-3YM variant should be used instead

Does this alternator fit my engine?

The dual-foot saddle mount 3.15" fits engines with a corresponding factory mount, including many Yanmar and Volvo units. Before purchasing, be sure to check the existing pulley and the foot spacing on your engine – if you are unsure, our support team will be happy to help you select the correct variant (including pulley and conversion kit requirements).

Individual or as a set?

The "individual" variant (SKU 752017006) includes only the alternator – suitable if you are already using or replacing a compatible Balmar regulator (e.g., MC-618) and temperature sensors. The "set" (SKU 752017065) additionally includes the MC-618 multi-stage regulator with temperature sensors and is the right choice for a complete new installation or if you want to upgrade from a simple internal regulator to a full-featured, temperature-monitored multi-stage charging system.

Application Area

Suitable for sailing yachts, motor yachts, and RVs with larger onboard electrical systems, planned or completed lithium conversions, as well as for situations with frequent engine idling, such as charging in an anchorage.

Are you unsure whether the dual-foot 3.15" mount fits your engine or if you need an additional AltMount© conversion kit? Contact our support team – we will help you find the right XT alternator for your onboard electrical system.