A method and apparatus are disclosed for providing a battery low voltage
warning for a range of batteries having various initial voltages. When a
battery is inserted into a battery holder its initial off-load voltage is
measured using a microprocessor. The microprocessor selects a suitable
voltage threshold, at which the battery is considered to be discharged,
from a predetermined number of voltage thresholds. The initial off-load
voltage of the battery is used by the microprocessor as a basis for
selecting a suitable threshold. An LED warning or the like is used to
indicate that the threshold is reached in use. A measurement probe is
shown which uses such a method and apparatus.