This is true. The technology that shows the battery percentage of Oraimo power banks was not well made; it is not showing the correct battery percentage of the battery.

Power banks swell for different reasons, and one of them is that when the power bank falls, the battery will swell. Heat could also cause it as well.

The most common issue with the Oraimo Power Bank is also the charging port getting spoiled. I don't know why, but I have noticed this as well.