I recall reading somewhere that the terminal voltage (open circuit) of a battery is not really a good measurement of whether or not that battery can perform its intended function. Is the terminal voltage an acceptable way to quickly ascertain a battery's status in general or does that depend on the type of battery?
I believe that the example given was an automobile battery. This type of battery has to be able to provide several hundred amps of cranking power in order to start the engine. Even if one measures around 12V at the terminals of the battery, it may still not be able to start the vehicle. Why is this so?