Should the car battery be replaced when its lifespan reaches 30%?

[VonSara]

The designed lifespan of a car battery is 27 months. For general family vehicles that are used conservatively, new car batteries often last 3-4 years. However, after the first replacement, they typically need to be replaced every 2 years or so. Battery maintenance methods: Frequent charging: Car batteries should be charged regularly. If left unused for a long time, the battery will gradually self-discharge until it becomes unusable. Therefore, the car should be started periodically to charge the battery. Regular cleaning: Clean the battery terminals periodically and apply specialized grease to protect the wiring harness. Regularly inspect the battery accessories and connecting circuits. Avoid using electrical appliances after turning off the engine: Using car electrical appliances after the engine is turned off is prohibited. Running the battery alone without the engine generating power can cause damage to it.

[SavannahAnn]

I think when a car battery's lifespan drops to 30%, it's usually recommended to replace it, because below 50% it becomes unreliable, especially during cold winter starts when it's prone to failing. I've experienced this before—my car suddenly wouldn't start, causing delays and extra towing costs. You can use a voltmeter to check the voltage; if it's below 12 volts and starting becomes difficult, it's best not to take the risk. In daily driving, frequent short trips accelerate battery aging, so regular maintenance checks are important. Safety first, after all—a new battery only costs a few hundred dollars, and replacing it early saves hassle and money. Getting stranded in a remote area would be even more troublesome, so I've made it a habit to check my battery's health every year.

[MacMila]

It depends on personal usage habits and budget. If the car is frequently used for long trips, the battery might still hold up, but 30% health indicates insufficient capacity, making it prone to issues like delayed starts or flickering lights. Replacing the battery costs around 500-1000 RMB, which isn't expensive. Compared to the potential cost of calling a tow truck or repairing other damaged components in case of failure, this expense is more cost-effective. You can regularly assess the risk by using a multimeter to measure current or observing the starting performance. From an economic perspective, investing early saves more—don't wait until the car completely breaks down to take action.

[VonKaleb]

A battery life of 30% indicates it's nearing failure. I recommend getting it checked at a professional shop immediately. They can use diagnostic tools to measure internal resistance or discharge state, accurately determining if replacement is needed. If the health is too low, winter driving poses significant risks, potentially leading to failure to start and unexpected breakdowns. Basic maintenance includes keeping the battery clean and fully charged, but if symptoms occur frequently, don't hesitate to replace it with a new one for safety.