Lots of car buffs say that the generator and an alternator are the same thing so there is absolutely no reason to convert. To support this particular argument, they do share exactly the same purpose to replenish the actual battery and run the particular lights. Both devices will also be belt driven and utilize crankshaft rotation to generate power, but this is where the commonalities end.
The alternator has the ability to of producing more electrical energy in lower RPMs than a power generator. This is probably the biggest benefit within upgrading. Generators are well known for not producing enough POWER current at engine nonproductive to meet the automobiles needs. An alternator has the capacity of outputting 90 Amps from idle whereas a heavy responsibility generator would produce under 20 Amps.