I go to start my car and starter cranks and turns very slooowly. I take it out and charge it at 12-amp for two hours and it works fine. How long should I charge the battery to make sure it gets its full capacity. A repair manual gave me two options. Load test the battery or use a hydrofomer. I'd just charge it overnight at 2-amp. Which of the three or any other ideas is a practical option to determine charged?
-TIA-