What does it mean when the car battery warning light turns red?

[MacRose]

Here are the specific reasons and solutions for when the car battery warning light turns red: 1. The alternator belt is broken, affecting the alternator's operation. When the car alternator belt breaks, the alternator loses its power generation driving force. Issues like the alternator belt being too tight, too loose, or slipping can also cause charging system malfunctions. To resolve this issue, replace the alternator belt and readjust its tension. 2. The alternator itself is damaged. Internal damage to the alternator, such as a burned-out rectifier plate or a slipping alternator drive pulley, may cause the battery light to illuminate. During inspection, use a multimeter to measure the alternator's rated power output. If it is below the normal range, replace the alternator. 3. Natural battery aging. If the battery has reached the end of its lifespan and can no longer store charge, the dashboard may display a warning light. When inspecting the battery, use a battery tester to determine if the battery is aged. If the issue is confirmed, replace the battery. 4. The battery terminals are oxidized, or there is a fault in the charging system wiring. Oxidized battery terminals can be restored by cleaning. For alternator wiring faults, check for loose connections, short circuits, or other issues, then develop a repair plan based on the specific problem.