How Much Does an Alternator Weigh? 

Every internal-combustion engine (ICE) vehicle has a 12-volt electrical system that centers around battery storage capacity and an alternator to produce and deliver electrical power. The alternator converts rotational force into electrical energy.

A passenger vehicle like your car, SUV, minivan, or half-ton truck will typically have an alternator that weighs in at between 12 and 15lbs and is about the size of a coconut. Alternators built for heavy-duty applications like highway trucks or machinery, will tend to be larger and heavier and can weigh anywhere from 16-50lbs, and even up to 100lbs or more for the beefiest models. 

If alternators are made of aluminum partly to save weight, why do alternators weigh so much for their small size? It’s because the guts of an alternator contain extensive windings of copper wire in the rotor and the stator. Copper is a fairly dense metal, so the wires that make up the windings end up weighing a fair bit and making up most of the weight in the alternator. 

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