7.1 General
Discharge testing of the battery is performed to determine the battery capacity. There are two
reasons for performing this test:
1. A rating test discharge – the intention here is to determine the percent of battery capacity as
compared to the rated capacity. This is typically an 8hour discharge test.
2. A service test discharge – this test is to determine the battery standby time under the actual
load conditions of intended battery usage. The rating test discharge is usually performed
using a suitably designed and sized load bank to provide a constant DC current load to the
battery. The test is performed for the specified period of time to an end-point voltage per
cell with the ampere-hour capacity of the battery calculated by multiplying the number
of hours of run time. The actual Ah capacity can be compared to the rated Ah capacity to
determine percentage capacity. This type of test is usually used as an acceptance test of the
battery. The service test is usually performed by placing the actual load on the battery and
determining the actual time the battery will support the load. This test is done, in the case
of a UPS, by switching into a test mode where the battery becomes the primary source and
the normal AC line becomes the backup. If the load is not critical, the AC input can simply be
shut off to simulate a loss of power event and total system operation can be verified as well.
A load bank can be used if the normal battery load is well defined.
7.2 Test Procedure
The battery test procedure for either test is:
1. Ensure the battery is fully charged before capacity testing and that all connections are clean and
tight. If the battery has not been on charge for at least one week, re-attach the charger, then do
the test after a week of the battery being on charge.
2. Prepare the load bank or test the load system. Ensure all temporary cable connections are
secure and connected to the proper polarity, and have sufficient current-carrying capacity.
3. Determine the battery temperature by measuring and recording the temperature of every 15
blocs.
For further technical support, please contact VALEN on the below details.
Section 7
Capacity Testing
9
INDUSTRIAL BATTERY & ENERGY STORAGE SOLUTION PROVIDER
AUS
1300 734 253 NZ 0800 734 253
