Most chargers go through several different steps before the battery is fully charged. When you re-connect the cable, the charger will restart safely, it will probably take 15min to run diagnostics again / and go through all the steps to confirm that the battery is fully charged.

1. CC (constant current) stage. This is the stage all the chargers use, and the only for most fast chargers. During the constant current stage, the battery is basically connected to a current-limited power supply, usually limited to 0.5-0.7 times the nominal battery capacity (that's from 0.5 to 0.7C) it lasts until the cell voltage reaches 4.2v. At the end of this stage, the battery charge is around 70-80%.

2. CV (constant voltage) stage or saturation charge. When the battery reaches 4.2v per cell, the charger acts as a voltage limited power supply, The battery voltage remains at 4.2v while the charge current drops gradually. When the charge current is between 3 and 10% of the labeled capacity, the battery is considered fully charged.

3. Topping charge. Depending on the charger and the self-discharge of the battery, a topping charge may be implemented once every 500 hours or 20 days. Typically, the charge kicks in when the open terminal voltage drops to 4.05V/cell and turns off when it reaches 4.20V/cell again.

Here is the steps for a CTEK Lithium battery Charger