I have had an issue with something causing my battery to have a cell go bad. I have taken it to the mechanic and they stated that the starter was causing it and replaced it last week. I went to start my car today and the battery was totally dead. I was told that they checked the alternator and it is fine as well as the tention on the belts. The battery I have now is about a month old and is a pretty good battery for cca. I have noticed that there is corrosion build up on the battery terminals. I clean them at every oil change. I am not sure where to go with trying to figure out what is causing this issue. Can you please help.
You may have a parasitic draw on the battery from something in the car.
There is a procedure for finding a battery draw like that.
You will need a digital ammeter and a jumper wire with clips on the ends to do this.
First rig any door switches so you can have a door open without triggering the interior lights and unplug the hood light. Remove one battery cable and attach the meter in series between the battery cable and battery post. Take the jumper wire and also attach it the same way. Leave the jumper wire on for at least 10 minutes to expire all the automatic timers. Now remove the jumper wire and read the meter. Anything over 50ma is too much draw. The way you locate this is to start removing fuses one at a time until the meter drops to normal level. This will be the circuit with something staying on. Determine what components are part of that circuit and check them individually until the problem is isolated.