Edited by Stephen J. Mraz

But brushless alternators have fewer moving parts to wear out, so they last longer. This lets the company warranty this alternator for three years or 350,000 miles. The 36SI is also efficient, needing less engine power to generate electricity, which leaves more to turn the wheels and pull the load. For example, when tested against a leading competitor, the 36Si saved $110 for every 100k miles driven at a 60-A load (with fuel at $4/gallon). At 80 A, that goes to $170 per 100k miles. The alternator also features Remote Sensing. It detects actual input voltage at the battery and tells the alternator to boost output to compensate for losses due to resistance in the cables and environmental factors. Research shows that if voltage is down by 0.5 V, charging times can double.

The unit weighs about 26 lb, is rated 68% efficient, and generates 97 A at 2,000 rpm and 165 A at 6,500 rpm. It can be hinge, pad, or quad mounted.

Heavy-duty