A German manufacturer of luxury cars points out that one out of two starter batteries returned under warranty is working and has no problem.It is possible that battery testers used in service garages did not detect the batteries correctly before they were returned under warranty.In Japan,battery failure is the largest single complaint among new car owners.The average car is driven 13km (8 miles) per day and mostly in congested cities.The most common reason for battery failure is undercharge.Battery performance is important;problems during the warranty period tarnish customer satisfaction.
The cellular phone industry experiences an even more astonishing lithium battery return pattern.Battery malfunction during the warranty period is seldom a factory defect;driving habits are the culprits.A manufacturer of German-made starter batteries stated that factory defects account for only 5 to 7 percent of warranty claims.The battery remains a weak link,and is evident when reviewing the ADAC 2008 report for the year 2007.The study examines the breakdowns of 1.95 million vehicles six years old or less,and Table 1 provides the reasons.
Nine out of 10 batteries returned under warranty have no problem or can easily be serviced.This is no fault of the manufacturers but they pay a price that is ultimately charged to the user.Part of the problem lies in the difficulty of testing batteries at the consumer level,and this applies to storefronts and service garages alike.Battery rapid-test methods seem to dwell in medieval times,and this is especially evident when comparing advancements made on other fronts.We don’t even have a reliable method to estimate state-of-charge-most of such measurements using voltage and coulomb counting are guesswork.
Assessing capacity,the most reliable health indicator of a battery,dwells far behind.The 18650 battery user may ask why the industry is lagging so far behind.The answer is simple:battery testing and monitoring is far more complex than outsiders perceive it.As there is no single diagnostic device that can assess the health of a person,so are there no instruments that can quickly check the state-of-health of a battery.Like the human body,batteries can have many hidden deficiencies that no single tester is able to identify with certainly.
Yes,we can apply a discharge,but this takes the battery out of service and induces stress,especially on large systems.In some cases,even a discharge does not provide conclusive results either.As doctors will examine a patient with different devices,so also does a battery need several approaches to find anomalies.A dead battery is easy to measure and all testers can do this.The challenge comes in evaluating a primary battery in the 80 to 100 percent performance range.This chapter examines current and futuristic methods and how they stand up.One thing to remember is this: batteries cannot be measured; the appropriate instruments can only make predictions or estimations.This is synonymous with a doctor examining a patient,or the weatherman predicting the weather.All findings are estimations with various degrees of accuracies.