What are the reasons for a battery not holding charge?
3 Answers
There are several reasons why a battery may not hold charge: severe sulfation of the plates, significant water loss, a short circuit in a single cell, or excessive impurities within a cell leading to rapid self-discharge. Below are some related explanations: Pulse charging method: Use positive and negative pulse charging to depolarize the battery, followed by a complete discharge. Repeat this cycle three times. If there are signs of capacity recovery, you can perform additional cycles for better repair results. Water replenishment repair: Only add deionized water or purified water when replenishing water. Avoid using tap water, as it can cause significant self-discharge issues in the battery. Car battery: Also known as a storage battery, it is a type of battery that works by converting chemical energy into electrical energy.
Having driven for twenty years, I've encountered several battery failures, and here's what I've found to be the most critical issues. First, the battery itself reaches the end of its lifespan—lead plates corrode or the electrolyte dries up, making it unable to hold a charge. Second, the alternator underperforms due to a loose belt or a faulty regulator, failing to charge the battery. The third and most easily overlooked issue is parasitic drain, such as incorrectly wired aftermarket dashcams that continue to draw power even when the car is locked. Last time, my car wouldn't start after being parked at the airport for five days—turned out the anti-theft module was leaking current. The fourth scenario involves frequent short trips where the engine barely warms up before reaching the destination, leaving the battery perpetually undercharged. Lastly, in winter when temperatures drop below -10°C, the electrolyte thickens like jelly, drastically reducing the battery's capacity. Seasoned drivers recommend keeping an emergency jump starter in the car—it can be a lifesaver in critical moments.
Last week, I went to the 4S shop to replace the battery, and the technician taught me several self-inspection methods. If the battery inspection window turns black, it indicates severe sulfation and poor charge retention; if the electrode posts feel hot, it suggests poor contact; listen for a clicking sound during startup to gauge the level of battery depletion. Daily care includes ensuring not to leave the reading light on, and for electrical modifications, always go to a professional shop for wiring—my friend ended up with a leaky battery after installing a cheap subwoofer. Avoid plugging high-power devices like car vacuum cleaners into the charging port randomly, and it's best to disconnect the negative terminal if the car is parked for more than half a month. Taking a half-hour drive each month helps keep the battery fully charged, and avoiding direct sunlight in summer can slow down aging. However, even if it still charges, it's advisable to replace the battery after three years—breaking down on the road is too dangerous.
