Why not show the BBU capacity 100% when its status is “OK” ?
Applied models:
ES-1640dc / ES1640dc v2 / ES1686dc / ES2486dc
Applied firmware:
All NAS firmware
Scenarios:
Why does the BBU capacity only show 67% instead of 100% after its status changes from “Learning” state to “OK” state.

Solution:
This is normal that the BBU status changes from "learning" to "ok" before the BBU capacity has not reached 100%.
Actually, from our specification, BBU status would change from "Learning" to "OK" once the BBU capacity reaches the threshold 60%. In addition, it would also continue charging till 100% at the same time.
Basically, the 60% BBU capacity is enough to support and complete the data protection and so its status changes to “OK”.