A battery tester is an electronic device intended for testing the state of an electric battery, going from a simple device for testing the charge actually present in the cells and/or its voltage output, to a more comprehensive testing of the battery’s condition, namely its capacity for accumulating charge and any possible flaws affecting the battery’s performance and security.
Battery analyzers were originally instruments used to restore nickel-cadmium batteries degraded by “memory” effects, a diminishment of capacity that arose when these batteries weren’t fully discharged. Today these instruments generally exercise battery packs of diverse chemistries, not just nickel-cadmium, to help decide when it’s time to retire packs that fall below some performance criteria.
Analyzers might perform operations such as discharging a battery to measure capacity, running the battery through charge, discharge, wait and repeat cycles; measurement of the internal battery resistance, discharging a battery at different current levels to simulate actual usage patterns, and rejuvinating a battery that has been over-charged.
On the other hand, battery test systems are generally found in research and development labs where they characterize battery properties. A test system might assess some of the same qualities checked via battery analyzers, along with several other parameters. Typical applications are life-cycle testing to simulate battery loading, as well as checking cell balance of multi-cell packs.