Which Battery Cable Should Be Disconnected When a Car Is Not in Use for a Long Time?
2 Answers
When a car is not in use for a long time, the negative terminal should be disconnected first, followed by the positive terminal. There is no need to remove both the positive and negative cables; disconnecting one end is sufficient to break the circuit and stop power supply to the vehicle's devices. Removing the negative terminal cuts off most of the standby power consumption in the car, allowing the battery to discharge naturally. When the natural discharge rate is very low, disconnecting the negative terminal can help the car remain parked for a longer period. Methods for car battery maintenance include: 1. Regularly clean the battery; 2. Reduce electrical usage when the engine is off; 3. Replace the battery periodically; 4. Start the car regularly.
When I first bought my car, I often had to leave it parked for months due to business trips, so I started researching battery maintenance. Veteran drivers always say disconnecting the negative terminal is the most reliable method—that thick black cable with the minus sign. Why? Because the car's chassis is usually connected to the negative terminal, so disconnecting it cuts off the entire circuit, eliminating the risk of short circuits and preventing the battery from slowly discharging and getting damaged. Don’t mess with the positive terminal—if a tool accidentally touches the car body, sparks could fly, which is dangerous. Once, I got lazy and didn’t disconnect it for just two months, and when I returned, the battery was completely dead, costing me unnecessary money. Now, I use a wrench to loosen the negative terminal clamp—just two minutes of work—and wrap the cable end with tape to prevent accidental contact. I also park in a dry, well-ventilated spot to avoid moisture corroding the battery terminals. Periodically checking the battery voltage ensures it’s ready to go even after sitting for six months. This habit has been a huge help—saving both hassle and money.
