Car died and mechanic said it was battery. I told him to check alternator but he never did. A couple days later the car died on us again. The battery was fried. I decided to replace alternator and get a new battery. It was working fine for the past 25 miles and then the battery light just started coming on. Is it most likely bad rebuilt Denso alternator? I also have a new serp belt and all new tensioners and pulleys.