What is the reason for the battery showing full charge immediately?
3 Answers
Possible reasons why the electric vehicle charger shows full charge immediately after plugging in: the charger may be faulty; the battery itself may be faulty; the charging circuit may be faulty. The electric vehicle may be severely discharged, causing the voltage to drop below the safe charging voltage. Here are some additional details: Solutions: Try replacing the charger and testing again. If it still shows full charge immediately after plugging in, then the issue lies with the electric vehicle; if it charges normally, then the problem is with the charger, and replacing the charger should resolve the issue; if the issue is with the electric vehicle's battery or circuit, it is necessary to visit a repair shop for professional inspection and replacement of the corresponding components.
Last time my car battery was the same, it showed full charge after a short while, but in reality, it drained very quickly when in use. This is most likely because the battery itself is too old and can no longer hold a charge. An old battery suffers from severe internal sulfation, which prevents it from storing more electricity, so the charger mistakenly thinks it's fully charged. It could also be an issue with the charging equipment, such as unstable voltage from the AC charger or an internal short circuit in the battery. I tried measuring the voltage with a multimeter myself, and it only showed around 12 volts when the ignition was on, which is clearly insufficient. Later, when I took it to a repair shop for inspection, they confirmed that the battery was dead, and replacing it fixed the issue. Don’t ignore such problems—otherwise, the car could suddenly stall while driving, which is very dangerous. It’s best to have it professionally checked in time to prevent future issues. Also, pay attention to the battery’s condition during regular maintenance, and be prepared to replace it after three to five years of use.
As a car owner, I've encountered a similar situation where the battery charges up rapidly as if in fast-forward, yet the car still struggles to start. It's likely due to severe battery aging—internal degradation from prolonged use; or perhaps the charger settings are incorrect, giving false 'fully charged' alerts; even poor contact at the battery terminals can cause this. Back then, I spent half a day cleaning the electrode terminals myself, but it didn’t help—I eventually had to visit the repair shop. Reflecting on it now, it's crucial to develop good habits: regularly check battery voltage and charging status, use appropriate equipment when charging, and avoid cheap chargers. If you experience this issue, act early to prevent roadside breakdowns—safety always comes first.
