Battery rapid-test methods
Battery capacity is commonly measured by applying a full discharge. While this method provides accurate readings, it is cumbersome, time consuming and wears the battery down unnecessarily. During the last 15 years, several rapid-test methods have emerged that eliminate the need for discharge, so the manufacturers claim. Introduced in 1992, AC conductance became popular in measuring conductance, from which CCA is estimated. This non-invasive method was hailed as a major breakthrough because the test only takes a few seconds and the instrument stays cool. Unfortunately, AC conductance is unable to read capacity and is of limited use for deep cycle batteries.
During the last five years, critical progress has been made towards capacity estimations. Cadex has developed a apple laptop battery,apple a1175 rapid-tester based on multi-model electrochemical impedance spectroscopy (Spectro?). The Spectro CA-12 injects 24 frequencies ranging from 20-2,000 Hertz. The signals are regulated at 10mV to stay within the thermal battery voltage of lead acid. The 24 slices from the frequency excitations are compared and the minute nuances analyzed. The instrument completes 40 million transactions during the short 15-second test.
Electrochemical impedance spectroscopy (EIS) is not new. Equipment using this technology has been in use for decades. A full-fledged EIS requires dedicated instruments and a computer to analyze the data. The set-up is expensive, requires trained staff for analysis and is so large that the machinery is moved on wheels. Furthermore, long calculation times make the system unsuitable for commercial use. The Spectro CA-12 has solved these problems by using powerful digital signal processors, but the heart of the engine lies in the patented algorithm.
As encouraging as battery rapid testing may be, the reader needs to be reminded that rapid-testers, such as the Spectro CA-12, are not universal instruments capable of measuring the capacity of any battery that will come along; they need a apple a1185 , apple m8403-specific matrix as a reference. On purchase of such a unit, the instrument includes one or several matrices that are automatically matched with the selected battery. Cadex is in the process of expanding the matrix library to eventually include all major battery types.
In time, measuring battery performance through non-invasive means will become the acceptable standard, making discharge methods redundant. Typical applications are: checking batteries to reduce false warranty returns, preventing unexpected downtime by assessing apple powerbook g4 , powerbook g4 15inch battery state-of-health before a breakdown occurs, and improving the reliability of battery operated rental equipment.
Designers of battery rapid-test methods tend to be overly optimists and create targets that may not be achievable outside the laboratory. However, multi-model electrochemical impedance spectroscopy represents a great leap forward and opens the door to an entirely new way of apple a1012 ,apple a1079 , apple a1078 , apple a1148 testing.
