Routine Maintenance uses Impedance testing - without any disruption or down time to the telephone system - to confirm that battery cells are operating within the manufacturer’s specification.

THE WHY'S AND WHEREFORES!
Battery impedance testing is now becoming the preferred solution in the ongoing maintenance of Stationary Batteries, particularly in the case of Valve-regulated Cells.

Whilst there may always be the need for some form of definitive discharge test regarding the absolute certainty of a batteries ability to support a specific load for a precise period of time, there will always be risks associated with this type of test.

MUCH EASIER THAN CHECKING ELECTROLYTE
The sealed type lead acid battery’s electrolyte cannot be extracted to measure its specific gravity and observe its appearance. This limitation has made it impossible to identify the state of deterioration of the battery by sampling the electrolyte, which has been the conventional method for determining the condition of open vented cells.

NO NECCESITY TO DISCONNECT THE BATTERY FROM THE LOAD
The most accurate method of identifying battery deterioration is to perform a discharge test using a capacity-testing constant current device in place of the normally connected output load. In the first instance this type of test entails leaving the telephone system vulnerable in the event of a mains failure during the test. Secondly, even at the conclusion of the test, the battery having been discharged to 95% of its capacity, will offer little by way of back up during the lengthy recharge cycle required.

Using an impedance meter eradicates system vulnerability during essential testing.

IMPEDANCE TESTING MEASURES:
Internal resistance (impedance)
Terminal Voltage
Terminal temperature

AVOIDING TEST ERRORS
Unlike some test equipment that relies on the battery under test to power them, the impedance meter uses its own internal power source. After all, the reason for testing any battery is to check its condition. If its condition is poor and unsure, it should not be the power source for its own test!