I replaced the alternator and the battery. The only sign of a low battery that shows is a slow crank, till eventually the battery drains and won't start and only crank. It charges fine on the highway and doesn't seem to give me much trouble. I got it all tested but nothing usuall shows up. No matter what I do o can't find what the issue is. I've narrowed it down to alternator not properly charging the battery correctly, but I could be wrong