The service life of lead-acid batteries is influenced by multiple factors such as design life, usage habits, and environmental conditions. To determine their service life, it is necessary to combine factory parameters, real-time status detection, and performance degradation performance. The following are specific methods and key indicators:
1、 Theoretical life assessment based on factory parameters
Design cycle life (key indicators)
Startup type battery: shallow cycle design, theoretical lifespan of about 300-500 times (discharge depth ≤ 50%).
Energy storage battery: designed for deep cycling, with a theoretical lifespan of 500-1500 cycles (discharge depth of 80% -100%).
Definition: The "number of charge and discharge cycles" that a battery can complete under specific conditions (such as 25 ℃, 50% discharge depth).
Category:
Viewing method: Instructions or shell labeling (such as "cycle life ≥ 800 times @ 80% DOD").
Warranty Period
Legitimate brands usually offer a 1-3 year warranty, during which performance degradation exceeding the standard can be replaced free of charge.
Example: A certain energy storage battery has a warranty period of 3 years and promises to have a capacity of ≥ 70% within 3 years, otherwise it will be replaced.
2、 Real time detection to determine health status (SOH)
The State of Health (SOH) of a battery is a core indicator for measuring its lifespan. SOH=(current capacity/rated capacity) x 100%, and can be calculated using the following methods:
1. Capacity testing method (most direct)
Steps:
Fully charge the battery and record the voltage (such as approximately 12.8-13.0V for a 12V battery).
Discharge at a constant current until the termination voltage (10.5V for a 12V battery), calculate the discharge time x current=actual capacity.
Example: A rated 100Ah battery takes 8 hours to discharge to the termination voltage (current 10A), then the actual capacity=8 × 10=80Ah, SOH=80%.
Tools: multimeter, discharge meter (such as smart load meter) or battery tester (such as Hima AR3620).
2. Internal resistance measurement method (rapid screening)
Principle: The internal resistance increases with the increase of lifespan. When the internal resistance exceeds 2-3 times the initial value, the battery is close to being scrapped.
Operation: Use an internal resistance tester (such as BT5210) to directly measure and compare the factory data or new batteries of the same model.
Example: The internal resistance of a new battery is 10m Ω, which increases to 25m Ω after 3 years of use and may have reached the end of its lifespan.
3、 Predict based on appearance and performance
Abnormal appearance signals, bulging/deformation of the shell, oxidation/corrosion of the terminals, leakage/acid overflow, and significant weight loss.
4、 Practical tools and detection frequency
Recommended portable tools:
Multimeter (measuring voltage): such as Fluke 101, about 200 yuan.
Intelligent battery tester (measuring capacity/SOH): such as Ulide UT513, about 500 yuan.
Internal resistance meter (professional level): such as Hioki 3561, suitable for batch testing.
Detection frequency:
Energy storage system: Capacity test once a month, internal resistance test once a quarter.
Automotive batteries: undergo a comprehensive inspection once a year, with a focus on checking before winter.
By regular monitoring and scientific maintenance, the turning point of the lifespan of lead-acid batteries can be predicted in advance, avoiding sudden failures while maximizing the utilization of the remaining value of the battery.
