When the ProCube display shows 100%, the battery can be removed for use and is close to full.
After reaching 100%, the ProCube will continue to charge the battery at a slower speed; this is called the top-up charge, which is visible by the still blinking charge indicator (top bar) / slow increase of added mAh capacity. The reason for this is to not damage the battery.
LP-E6/E6N/E6NH | LP-E6P | LP-E8 | LP-E17