The only problem is a lack of adequate current capacity. Most stovebolt generators are either 25 or 35 amp units, so if you have enough accessory equipment to exceed that current draw, the generator will be running at full output all the time, and the battery will have to make up the difference. Some current hogs are electric cooling fans, high-output headlights, and some types of climate control systems with high current draw blower motors, A/C clutches, etc. Sound systems with high-wattage amplifiers put lots of load on an electrical system, too.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!