I hate electrical problems.... charging

somehow, my car does not want to keep a charged battery. in the past few months i have done the following.
replaced and tightened alt belt
replaced the alternater
replaced the voltage regulator
replaced the starter
replaced the battery and terminals
bypassed the ammeter

if i charge the battery, it will be fine starting for a few days. but after driving it for a while, the battery drains and eventually it will leave me needing a jump, or very close to it. I tested the voltage at the battery and it reads around 14.3 at idle.... so why is it not charging?