Hi, I have been having issues with my battery for 2014 Honda Civic (70,000 miles). I think it is the original. I had driven my car for errands and after driving 35 miles, the car took 7 tries to get the motor started and the battery, alternator, and starter tested good. Three weeks later, the same thing happened after letting the car sit for an hour and driving 35 miles, the car would not start and the battery needed to be jumped. The following week, I had the battery tested at the dealership and one day it was good and the next day it failed. The car sat overnight and the dealer is 35 miles from my house. What could the problem be in terms of electrical issues? I replaced the battery per recommendation after the failed test. Thank you.
Even though the charging system checked out good and you replaced the battery doesn't mean you don't have a problem. Recheck the charging system for proper operation with the new battery to see if it is charging within the manufacture specs.
A voltage draw on the battery can drain it over night. This means that something is staying on. Check for a draw on the battery.
This can be a complicated procedure so I recommend you take it to the dealer or qualified mechanic to have the car check for a parasitic draw.