Here's what could be happening and steps to troubleshoot:
1. Check the battery connections: Even though the battery is charged, ensure the terminals are clean and securely connected. Corrosion can prevent proper current flow. Clean them with a wire brush and baking soda solution, then reconnect.
2. Check the fuses: Check the main fuses in the fuse box (usually under the hood or in the cabin) and specifically those related to the starting system and the radio. A blown fuse could be preventing the car from starting, even with a charged battery.
3. Test the battery voltage: Use a multimeter to check the battery voltage. It should read around 12.6 volts when fully charged. A lower voltage indicates a problem with the battery itself or the charging system.
4. Jump start the car: Try jump-starting the car from another vehicle with a good battery and cables. If it starts, this points to a problem with the battery, its connections, or perhaps a failing alternator (although less likely given it's a seemingly sudden issue).
5. Check the starter motor: If jump starting doesn't work, the starter motor could be faulty. This requires a mechanic to diagnose and possibly replace. It's less likely the starter is the sole issue after the stereo noise, but it's a possibility.
6. The car's computer system: A deeply discharged battery *can* cause problems with the car's computer system. Sometimes, this requires a professional scan tool to diagnose any fault codes that might have been triggered by the low voltage event. This is a more serious possibility given the circumstances.
If jump starting doesn't work, don't keep trying. You risk further damaging the electrical system. At this point, you should:
* Call a roadside assistance service: They can jump start your car, and if the problem persists, they can tow it to a mechanic for diagnosis.
* Take it to a mechanic: A mechanic will have diagnostic tools to determine the exact cause of the problem, which could range from a simple fuse to a more complex electrical issue related to the low voltage event.
The stereo trying to eject a CD when the battery was dying suggests there might be more than just a low battery issue at play. Don't assume the recharged battery fixed everything. Professional help is likely needed.
