How to Determine if the Battery is Fully Charged?

[DeCharlotte]

Methods to identify a fully charged battery are as follows: 1. Judging by charging time: For a typical household car, the battery capacity is usually 60Ah, and the required charging current is one-tenth of the battery capacity, which is 6A. Charging at this current usually takes about 5 hours to fully charge the battery. If using a lower current, it may take around 10 hours to fully charge. 2. Judging by battery current: Use a multimeter to measure the current. When the displayed current value is about 2% of the battery capacity and remains stable, it indicates the battery is fully charged. 3. Judging by battery voltage: A 12V battery's actual voltage is slightly higher, typically around 13V when unloaded and no less than 11V under load. When the battery voltage reaches 13V as measured by a multimeter, it indicates the battery is fully charged. 4. Judging by observing the electrolyte state: When bubbles appear in the battery's electrolyte, it indicates the battery is fully charged. If direct observation is not possible, you can also listen for sounds to determine.