ok. first, your reply seems a little condescending. I may not be a certified mechanic but come on, why belittle people when they are trying to find some help. Most people work on their own cars in order to save money. also I may have worded my question improperly, but I am not totally incompetent.Let's start by IDENTIFYING the problem...
Your subject says "bettery keeps discharging" - the body of your post says "aerio not charging battery" - those are two different things.
If the car is not charging the battery, the battery will eventually run down because of the power being drawn from it, the battery itself can also be defective and incapable of holding a charge, or you can have an electrical load that is not being switched off that drains the battery when the car is not being used.
If you lack the test equipment and knowledge to determine which of the three scenarios you're being faced with, take the car to someone who does.
It's not charging.Volt readout at battery terminals;
12.95 car off
12.58 car on