I came back from a four day trip last week and my 2017 Hyundai Elantra would not start in the building parking. The dash lights were weak and the engine only clicked. I felt a bit silly standing there with my bags and a dead car. A neighbor gave me a jump, and it started fine, but I am not sure I trust it now. The battery is about two years old, so I did not expect trouble yet. My brother says four days is nothing and the battery must be bad. My coworker says even a good battery can lose charge when a car sits in the heat, because the alarm and the clock keep drawing a little power. A friend told me to check the date code and test it at a shop before buying a new one, since the problem could also be a weak charging system. Another guy said I should look at the terminals for white powder, which I never thought about. I read a page on in the evening to understand the size group, the capacity and the starting power, and I saved a few notes on my phone. My office is near the World Trade Centre, so I started looking for a Reliable Varta D47 battery near World Trade Centre, but I am still not sure if D47 is even the right size for my car. My questions are easy. How can I confirm the size if the old label is faded? Should I test the battery first or just replace it? Do shops here usually fit it while you wait? And how long should a good battery last if the car sometimes sits for a few days? Please share what happened with your car. Thanks for reading.