Battery tester (battery analyzer)

Battery testers (also referred to as "battery condition indicators, battery analyzers") are designed to indicate the condition of an electrochemical cell or battery. Battery testers permit the user to visually determine whether a cell needs to be replaced. Batteries are often tested to determine whether they are capable of being charged or whether they are no longer capable of functioning. Batteries of all types, whether frequently or rarely used, discharge with the passage of time. Accordingly, when placed into service, the battery or batteries that provide the energy source for electronic equipment may or may not have sufficient charge to power the equipment. For example, automotive batteries are required to operate under widely varying loads and at widely varying temperatures. A lead acid battery is mounted as a secondary battery on a vehicle such as an automobile so as to serve as energy source for starting an engine, illumination, fuel injection device. The vehicle storage battery is monitored to determine battery capacity, state of charge and certain fault conditions. As a consequence, a variety of devices have been proposed whereby a user can determine a battery's energy level with reasonable certainty. A battery analyzer is useful in various battery-powered electronic applications for testing charge on a battery and informing a user of the battery voltage level. The battery tester may be used in a battery level indicator to warn when failure of the battery is impending. The battery tester may also be used in a battery charger controller to determine whether a battery is charged, thereby preventing overcharging and damaging of the battery.