What Does the Battery Positive and Negative Symbol on the Car Dashboard Mean?

[OIsla]

Dashboard showing the battery positive and negative symbol indicates that the alternator is not working, and the battery power will be depleted quickly without replenishment. Below is relevant information about the alternator: 1. Car Alternator: The car alternator is the main power source of a vehicle. Its function is to supply power to all electrical devices (except the starter) and simultaneously charge the battery when the engine is running normally (above idle speed). 2. Precautions: Regularly clean accumulated dirt and dust on the alternator's surface to maintain cleanliness and ensure good ventilation; When installing the battery, avoid incorrect connections—typically, connect the positive terminal first and do not connect the ground wire, otherwise it may easily burn out the diodes.

[Bridget]

I've been driving for over ten years and seen it all. When that battery symbol with the plus and minus signs lights up on the dashboard, it's warning you about a charging system issue. Simply put, either the battery is failing or the alternator isn't working properly, preventing the battery from charging. The alternator is responsible for charging the battery while the engine runs - if its belt is loose, worn, or the wiring connections are corroded, the voltage drops, triggering the warning light when the computer detects an abnormality. If not repaired promptly, the battery will gradually drain, making sudden engine stalls especially dangerous, particularly during long trips. I've fixed this several times myself. First step: use a multimeter to check battery voltage with the key in the 'on' position (but don't start the engine) - normal reading should be around 12.6 volts; after starting, it should read above 13 volts. If readings are off, get the alternator checked or replace the battery at a shop. Regularly cleaning battery terminals can prevent this issue - too much corrosion causes unstable current. Make it a habit to self-check every couple months to avoid major headaches.