IEEE and NERC both require battery capacity testing as a means of predicting a battery system’s ability to perform when called upon during a loss of AC power, for acceptance of new installations, and in determination of end of life criteria for system replacement. While NERC is very vague and just states that “Capacity testing must be done at said interval”, IEEE 450, 1106 and 1188 have clearly defined frequencies, prerequisites and instructions on how these tests should be conducted.

From results that are submitted to us for warranty consideration or review, a group of common errors have come to light. Below are the top 5 most common mistakes that are seen in capacity testing.