Let me explain, when charging his phone and that it is full, it sends a signal to the charger saying STOP, and there the drop shipper the current minimum to maintain the loaded laptop.
OR, the charger reduces charging anything and constantly mobile, who does not like at all!
Fortunately, a security system that the phone rings for the disconnects that.
THUS, charger good for troubleshooting, but long term can screw up your laptop!