The charge levels of the cells within the battery pack are out of balance.
Some cells become fully charged before others, which causes charging to terminate early, before the entire battery pack is fully charged.
Ending recharging prematurely effectively reduces the available capacity of the pack.
Circuitry within the battery pack corrects such errors normally, but can take tens of hours to complete.
If this error is not fixed after 24 hours, or if the error reoccurs after it fixes itself, the error is likely indicative of a problem in the battery cells. In such a case, replace the battery pack.
No service action required, use the console to manage the node.
Wait for the cells to balance.