My car would not start after a recent heavy rain. The next morning my husband tried to jump start the battery and the car did not start. He removed the battery and the battery box was full of water. He removed the battery and drained the water. He put the battery on the charger and it was eventually good and it started the car. What I need to know is why the battery box filled with water and where it might have come from? Took the car to the dealer and they checked the battery, and it was good, of course. Any ideas on where they should look to see where the water might have come from that flooded the battery box? Dont know if it matters, but car is a Honda Civic Si 2018. Thanks for any help!