What Causes a Battery to Not Hold Charge?
2 Answers
When a battery fails to hold charge due to severe sulfation or water loss, and its exterior shows no damage, bulging, or signs of short/open circuits, the following repair methods can be attempted: 1. Charging: Perform depolarization charging using positive-negative pulse charging, followed by a complete discharge. Repeat this cycle three times. If capacity shows signs of recovery, additional cycles may enhance the repair effect. 2. Water Refill: Only use deionized or purified water for refilling—never tap water, as it can cause excessive self-discharge. Most modern batteries are maintenance-free, though older models may allow electrolyte top-ups. Avoid prolonged use of audio systems or air conditioning after engine shutdown to prevent deep discharge. Typically, batteries last 2-3 years.
I've encountered the issue of a battery not holding charge several times, usually due to battery aging or internal plate short circuits. After several years of use, old batteries experience reduced capacity and can't retain much power. It could also be caused by improper charging, such as a faulty alternator or a loose belt leading to insufficient charging output, leaving the battery in a semi-charged state for extended periods until it fails. Additionally, low electrolyte levels – whether frozen in cold weather or evaporated in high temperatures – affect charge retention. My advice is to first check if the battery has expired (typically lasting 3-5 years), then use a multimeter to test voltage; if it drops significantly during ignition, it's likely faulty. Also verify alternator output (around 14V is normal). Regularly top up with distilled water to maintain proper fluid levels, and warm up the car for a few minutes before parking in winter.
