Any charging system, even a generator, can overcharge a battery if the voltage regulator malfunctions. Even a 200-amp alternator cannot supply more current than the battery can accept, unless the voltage control goes bad. The alternator will simply supply all the accessories' demand, and then use any leftover capacity to recharge the battery.
When I was running a truck shop, a local trucker brought me a "Skipper 600" (600 watt) linear amplifier to install for his CB radio. The FCC power limit is 5 watts, BTW! I used #1 welder cable to wire the power to the linear, and he took off from central California to New York on a turnaround trip. Two weeks later, he's back, saying "The radio talks fine, but my headlights go dim every time I key the mike!" Of course- - - -because the linear was drawing 75 amps, and he had a 60-amp alternator on it! I put a 200-amp brushless alternator on, and solved his problems!
Jerry
