1. Performance Degradation Assessment (Most Common Replacement Scenarios)
Sudden Drop in Range Exceeding Normal Degradation Range: After 2-3 years of normal use, if the battery life drops to less than 50% of the original rated range (e.g., it used to last 8 hours at full brightness, but now only lasts less than 3 hours), after ruling out usage habits and temperature effects, this indicates severe battery capacity degradation and requires replacement.
Abnormal Charging and Discharging Characteristics: If the battery shows "fully charged and turns green" after 1-2 hours of charging, but the battery level drops significantly within 5-10 minutes of use (phantom charge); or if it fails to fully charge after more than 8 hours, or the battery becomes abnormally hot (over 40°C) during charging, and the problem persists even after replacing the original charger, this indicates battery failure.
2. Appearance/Safety Risk Assessment (Must Replace if Inspected)
Inspect the battery compartment. If you find bulging, deformation, damaged casing, leakage, or rust/corrosion on the terminals (even after cleaning), even if it still functions normally, immediate replacement is recommended. These types of faults pose a short circuit and fire risk.
3. Determination of Exceeding Service Life If the battery has reached its designed service life and is accompanied by any of the above abnormalities, it is also recommended to replace it: the designed life of lead-acid batteries is 2-3 years, ternary lithium batteries are 3-5 years, and lithium iron phosphate batteries are 6-8 years. After exceeding the service life, the battery performance will continue to decline, and the safety risks will also increase.
