How To Check If Your Car Battery Is Dying. AutoZone provides this service for free. A more helpful way to interpret that battery light is that its warning you that your car is running only on battery power.
9 WARNING SIGNS THAT YOUR CAR BATTERY MAY BE DYING. When you hear the engine of your car cranking slowly take your car for a checkup as soon as possible. If the lights seem dimmer than usual then it probably means its time to replace the battery.
Make sure the vehicle is parked on level ground with the parking brake on and wear your safety glasses.
Its been a while. Cold cranking is hard work. The Check Engine light is a catch-all warning telling you something is wrong not necessarily something related to your battery. The shade-tree mechanics test is to disconnect the battery while the engine is running and see if it immediately wants to die.
