Testing Battery Capacity

Batteries in the BBU need to be replaced periodically. A battery test should be run every four weeks in order to get a reliable estimate of battery capacity, and to determine when it needs to be replaced.

The battery test is used to measure the battery's capacity to back up write data. In order to make a reliable estimate of battery capacity, the BBU pre-charges the battery before it proceeds with a full discharge cycle. The battery is automatically charged again after the test completes. The whole process usually takes between 8 and 12 hours.

While running the battery test and until charging is completed, write cache is temporarily disabled.

For how to replace the battery, see the installation guide that came with your controller.

To test the battery in a BBU

On the menu bar, choose Monitor > Battery Backup.

On the Battery Backup Page, click the Test Battery Capacity link.

When a message cautions you that testing the battery will disable the BBU for up to 24 hours, click OK to continue.

After the battery test starts, you will see the voltage start dropping; eventually the battery voltage will say "LOW". This is part of the battery test. After the voltage drops to a point, it will start charging again, and the status will change to "Charging." Eventually, the battery voltage will say "OK" again.