How to Identify a Good or Bad Battery?
2 Answers
Methods to identify battery quality: 1. Leakage check: The battery contains corrosive chemical liquids that must not leak. A qualified battery ensures no leakage occurs regardless of vehicle bumps or even rollovers. 2. Cold resistance: Genuine batteries maintain a voltage above 7.2V required by the vehicle in low temperatures, with no decline in charging capacity. Inferior batteries struggle to maintain voltage above 7.2V in cold conditions and have poor charging capacity. 3. Vibration resistance: Inside the battery, there is a metal plate fully immersed in liquid; their chemical reaction generates and stores electricity. In genuine OEM batteries, the power-generating materials remain firmly attached to the plate no matter how much the vehicle shakes.
I commute by car daily, so I can easily tell if the battery is good or bad. If the engine cranks slowly or makes a squeaking sound when starting, or if the dashboard lights flicker, these are signs of a weak battery. Pop the hood and inspect the battery directly: white or green corrosion on the terminals, a bulging case, or fluid leakage are clear indicators of trouble. A simple test is to measure the voltage with a multimeter when the engine is off—normal readings should be around 12.6V. If it’s below 12.2V, it’s time to replace it. Once, my aging battery failed to start in the morning, delaying my commute. I promptly replaced it and now make it a habit to check before winter each year to avoid dangerous breakdowns on the highway, especially since cold weather increases the risk. If unsure, test the headlight brightness stability using your phone.
