How long does it usually take to charge a car battery?
3 Answers
Car starting batteries generally require 20 hours of charging. Below are some charging precautions: 1. Do not completely disconnect the vehicle's power: Some cars cannot have their power completely disconnected. Therefore, if using a charger, connect it directly to the battery without removing it, otherwise data loss may occur, requiring initialization, commonly known as decoding or code matching. 2. Regular charging: If the battery voltage is 10% lower than the rated voltage, i.e., below 10.8V, the battery is at risk of discharge. It should be fully charged once a month. 3. Timely recharging: When the battery is severely discharged, supplementary charging is necessary. The charging capacity from the car itself is far from sufficient, so a charger must be used to charge the battery.
After driving for so many years, I feel that battery charging time really depends on the situation. When I used my old car, that worn-out battery was almost dead, and it took a whole night to charge. Now, with the new car's battery being much better, it usually takes about 8 to 12 hours to get it mostly charged. The key factor is the battery capacity—for example, a 50Ah battery with a 5A slow charger takes roughly 10 hours. If the battery is completely drained or severely aged, it might even take over 15 hours. Don’t rush with fast charging—while it can finish in 1 to 4 hours, it can easily damage the battery’s internal structure and shorten its lifespan. Before charging, I usually check the battery’s state with a voltmeter. If it’s below 12V, it’s time to charge, and after charging, I verify it’s around 12.6V. Always ensure proper ventilation to avoid smoke or fire. Regular maintenance of the battery terminals and cable connections can save a lot of trouble.
When I first bought my car, I was also confused and thought I could leave after charging for just a few minutes, but it ended up taking a long time. The charging time for the battery depends on its size and the type of charger—using a regular home slow charger takes 8 to 12 hours for safety. Fast charging can get it done in 1 to 4 hours, but frequent use can damage the battery. Last time I used fast charging, my battery's range noticeably decreased. You also need to consider the battery's condition: a new battery or one with a light discharge might only need 6 to 7 hours to fully charge, but if it's been completely drained for too long, it’s common for charging to take over 15 hours. Don’t just focus on the time—make sure the charger’s power matches the battery capacity, and always charge in a well-ventilated area to avoid risks. Here’s a handy tip: using a mobile app to monitor the charging process makes things much easier.
