Summary
RCM gained prominence with air transport in decreasing failure and reducing maintenance costs. Batteries are also gaining importance but before RCM can be implemented in earnest, more effective battery diagnostic technologies must be developed. Batteries use different criteria than wear and tear on a mechanical part and observe capacity, internal resistance and self-discharge.
• Capacity represents storage capability that is difficult to measure on the fly. Coulomb counting is well-suited to measure the capacity of Li-ion. Electrochemical impedance spectroscopy (EIS) checks lead acid and Li-ion by a frequency scan.
• Internal resistance governs current delivery. Ohmic values are simple to read but the numbers do not correlate with capacity. Resistance tends to stay low throughout life while capacity drops predictably as part of usage.
• Self-discharge reflects the mechanical integrity of a cell. Li-ion has low self-discharge; elevated self-discharge hints to stress-related damage than can compromise safety. Modern battery analyzers measure capacity, internal resistance and self-discharge.
Reducing our dependency on fossil fuels places new responsibilities on the battery. Advancements in Diagnostic Battery Management (DBM) will eventually usher in RCM as a battery maintenance tool.
Improvements in batteries do not rest in higher capacity alone, but in delivering a dependable and safe energy source over the entire service life of the battery. DBM assists in battery development by keeping batteries in service longer, lowering operational costs and reducing the environment impact of fabricating and disposing of batteries.
About the author: Isidor Buchmann is the founder and CEO of Cadex Electronics Inc. For three decades, Buchmann has studied the behavior of rechargeable batteries in practical, everyday applications, has written award-winning articles including the best-selling book “Batteries in a Portable World,” now in its fourth edition. Cadex specializes in the design and manufacturing of battery chargers, analyzers and monitoring devices. For more information on batteries, visit www.batteryuniversity.com; product information is on www.cadex.com.
Back to HCB News
