Hi, my 91 Geo Metro has a 3 cylinder engine. Recently, I'm losing the charge on my battery, also the engine is having trouble making it up the mountains up to Black Canyon City in AZ from Phoenix. The engine stutters when accelerating. Autozone tested the alternator but said it is good. They also tested my battery and recharged it saying it is good as well. When going uphill, I steadily decellerate down to around 40mph on the freeway and can't get any speed going uphill. I'm afraid that I might have to spend the night in the car again if something happens. Any idea?