Thor Forums

[Chance]

Originally Posted by Beau388

One thing I did notice was the alternator's relatively high cut-in rpm and wondering about the high rpm capability. Fords 175 amp alternator on the V-10 has a 1,600 rpm cut-in, max of 175 amps @ 6,000 rpm and a 18,000 rpm ability. With a 3:1 pulley ratio that gives 30 amps at 800 engine rpm and only 15,600 rpm at engine red line. Volta rpm curves are 4,000 rpm cut-in and max shown of 8,000 rpm but one would hope it will stand at least 16,000 rpm; otherwise there only use will be on big diesels with limited rpm capability.

Just an educated guess based on my experience: Larger items normally can’t rotate as fast due to physical limitations. The alternator that Volta uses I expect is physically larger because it puts out a lot more power. If indeed larger, it might not be able to take 16,000 to 18,000 RPMs.

The bright side is that “if” it is physically much larger, it can then also handle more heat dissipation which means more power at steady state. That’s got to be important with alternators that make close to 10 kW or more.

Notice many of the new 48-Volt motor/generators on mild hybrid engines have external liquid cooling. The Volta I believe has air cooling, so may need to be a little larger.

Speed in itself shouldn’t be much of an issue since belt drive can provide different ratios as needed. Volta is being used on Winnebago Travato which has a high-reving DOHC V6.