This could be a result of a number of things. Auto Zone can definitely help with this problem if you take it to the store located nearest to you. The most likely problem is that there is a bad cell in the battery which means you would need to buy a new one.
Take it to your local auto parts chain store. Most of them will check your battery and alternator for free.
Maybe your alternator needs replacing.
Sulfation can happen when battery is not fully charged and remains discharged
It could be a faulty battery, If you have bought a new one recently, and it still wont stay charged, its probably your altenator. good luck or it may be the altenater.
Then something is on pulling power from the battery. Any light on the vehicle or any relay that is stuck closed.
Dead cell in battery or something is on pulling power from the battery. Disconnect the negative battery cable overnight with the battery fully charged (12.6 volts). If the battery is dead the next morning it has a dead cell and needs replacing. If however the battery is still fully charged then a light is on somewhere or a relay is stuck closed.
it wont work anymore. have it tested before replacing could be it is not being charged properly Most auto parts stores will test your battery and charging system for zip.
disconnect the positive lead from the battery with everything off. Then touch it gently to the battery post , if you see a spark there is something drawing current
It might need a new battery.
Dead battery
The voltage regulator and or the alternator are bad. You need to have these items checked. Make sure the wiring is in good shape and battery cables are in woking order.
Your alternator is probably rebuilt and not really new. I have had this problem several times and I have bought a new battery and alternator. The alternator keeps your battery charged and powers your electrical system, so even when driving you can lose all power in the car from the alternator draining your battery. Take the battery and alternator to an auto store and they will test both for free. Ask them about the difference in a rebuilt alternator and a brand new one. This is a very common problem.