Heavy Duty Alternator

55SI Alternator: Powerful—and then Some


When you need the most power possible, nothing but the Delco Remy 55SI alternator will do. The 55SI, another durable Delco Remy brushless heavy duty alternator, is the highest output machine on the market.Designed for vehicles with significant electrical loads, the 55SI is available in both 12 and 24 volts and used on a number of applications where maximum alternator performance is required. Its compact size – nearly half the size and weight of the competition – supports all current commercial applications with the alternator engine pad mount design.But it’s no lightweight, mind you. With the highest amp per pound performance rating in the market, the 55SI is at the top of its class.“The 55SI is the highest output Delco Remy alternator—not to mention the highest output machine in its class,” says Tim Barnes, Delco Remy Product Manager. “No other alternator can provide this combination of performance, a brushless design and an efficiency rating of over 80% in this frame size.”

The 12-volt model is commonly used by municipalities for utility/work trucks to power inverters and plug-in power tools, lights and other electrical equipment. This 12-volt model also supports the fire and rescue truck market with the output they need and in a package they want. One 55SI can replace a dual alternator system, therefore freeing up space under the hood for other accessories. It’s also ideal for highway trucks equipped with multiple battery auxiliary power units (APU).

The 24-volt model meets the high electrical load demand of  wheel loaders, graders, mining equipment and other off-highway vehicles. 

Now and in the future

One of the most attractive features of the 55SI is its future-readiness.

“Highway trucks are becoming more sophisticated each year. Today’s battery APUs and all the additional truck electrical loads are growing—and the 55SI is ready,” explains Barnes. “The 55SI is already there. As the electrical needs of long-haul trucks continue to grow, the 55SI will remain a viable option. It was purposely designed to handle today’s electrical needs as well as what’s to come in the next several years, all with the brushless durability trucking fleets require.”
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