The car, a 2007 Corolla CE, was purchased brand-new and driven off the lot on december of 2006. It now has 53,000 miles. The battery is the original OEM and according to the label, was made by Johnson Controls. Today I had some trouble starting the car. The first time, it made a rapid clicking sound, it sounded electrical. I thought, "maybe it's the battery," so I turn the key towards 'ACC' and then turn on the fan at full power. It works fine, didn't feel weak at all. The dashboard lights were at full brightness, did not seem dim at all! I try to start the car again, it made the rapid clicking sound again for about 10 seconds, but eventually I hear the engine cranking but VERY SLOWLY, it sounded like it was struggling but finally the car starts!!! I drive the car home with the intention to research the topic further. Some hours later, I try to start the car again. This time, no rapid clicking but it would struggle to crank and it cranks very slowly, taking perhaps 15 seconds for the car to finally start but it does! So, is it the battery? Why it might NOT be the battery: 1. Car started just fine yesterday. Do batteries just fall off the cliff? Wouldn't deterioration be gradual rather than sudden? 2. After struggling to start the car, I turned on the fan and the radio and both worked fine--at full strength! The dashboard lights appear bright and vivid. Dim dashboard lights often indicate a depleted battery. 3. Battery is not that old. So, is it possible for a battery to be able to power the fan and other accessories perfectly well but NOT be able to crank the engine? Or, is that a paradox?