Do You Need to Disconnect the Wires When Charging a Car Battery?
2 Answers
You do not need to disconnect the wires when charging a car battery. Disconnecting the positive and negative terminals of the battery may cause partial data loss in the ECU. Steps for charging a car battery without disconnecting it: 1. Connect the positive terminal of the charger to the positive terminal of the battery; 2. Connect the negative terminal of the charger to the negative terminal of the battery to begin charging. Precautions for charging a car battery: 1. In cold weather, check if the electrolyte is frozen before charging. Do not charge a frozen battery as it may cause an explosion; 2. Before charging, check the electrolyte level. Do not charge if the electrolyte is insufficient; 3. During charging, measure the density and voltage of the electrolyte every hour and monitor the temperature.
I always disconnect the negative terminal when charging my old car for safety. Last week, when helping charge my dad's decade-old Lavida without disconnecting it, a faulty charger burned a small capacitor in the dashboard, costing over 400 yuan to repair. Lesson learned: now I first remove the black negative clip, then the red positive one (order is crucial!), and connect the charger clamps directly to the battery posts. This way, even if the charger shorts, it won't affect the car's wiring. However, with some newer start-stop vehicles, disconnecting the battery may reset the system—better check the manual or use a stabilizer when charging.
