Impedance testing the batteries is a way of determining the internal resistance of each battery in the string. The benefits of impedance testing are:
Non-intrusive testing which means that the batteries will not require charging following the completion of the tests.
The UPS can be left in operation supplying the load as only the battery string being tested requires isolating.
The tested battery impedance can be compared to manufacturers specification and any faulty individual batteries can be quickly identified.
A trend can be established if the batteries are tested annually to monitor the rate of deterioration.
Full report can be provided upon completion.