My question is whether my laptop's battery suffers (the runtime is shortened) if I have always connected it to the charging cable, even if the battery is completely full or the laptop is switched off.
If the laptop is constantly connected to the power, the battery is permanently charged. The number of charge cycles affects performance.
Yes, continuous charging damages the battery
Only the manufacturer of the laptop and the battery probably knows that. If the battery is full, there's no need to charge it. Could recognize software or hardware.
The charging technology decides about it. It can be different with every laptop.
In the manual of the laptop we will tell you what.
