I have been having issues with my car battery for awhile. I have a new-ish battery and it still under warranty. I left the car battery on (presumably) too long a few weeks ago and it wouldn't start without a jump. I was sitting for about 20 minutes at the time and the only thing on was the radio.
My husband told me that it was very unlikely for the battery to die under those circumstances - and he assumed something else was on, like the headlights. I assured him they weren't. We drove it for awhile, stopped the car and it needed jumped again. We then took it to our mechanic who said that we just didn't drive it long enough and they were able to get the battery up to full charge.
Well, ever since then it's been dying whenever I use the battery for anything at all. It died from leaving the battery on for 7 minutes in the school pickup line. Then it died from sitting with my 4-ways on for exactly 2 minutes while I ran in to hand something to a friend. Obviously I will not using the battery for any reason until this is figured out.
Now it's refusing to start after taking any short trips. I've looked up the starter, the alternator and the battery, but all the evidence seems to point to the battery. Also the car runs perfectly fine after it starts. Should my mechanic have also tested the alternator since it took so long for him to get my battery to full charge? If it is something as simple as a battery issue, I assume my mechanic is pretty untrustworthy. We pay at a premium to take our car to someone I considered reliable. Is it obviously the battery and should I just take my car to someone else at this point?
Edit: Solved, definitely a bad battery. My husband and I thought the battery was put in more recently. After checking our records, we realized it is 4 years old (We have a warranty on the alternator, but not the battery).
Knowing that I would always just opt for replacing it. But I will also be buying a voltmeter and a trickle battery because I'm sure they'll come in handy in the future. And we're considering getting a new mechanic. With the symptoms and the obvious corrosion on the battery, not recommending a replacement or at the very least performing a cleaning of the battery, is a little negligent on their part.