Battery defective in the laptop data is lost?

My notebook I operate because of defective battery with the power supply now I have concerns whether there's not lost data if I do not work with it for a long time and disconnect the power supply.

Insofar as you always drive the laptop down properly and treat it well, do not drop it or throw something on it, nothing should happen.

Your data is still there, the hard drive does not need power when not in use

With an SSD (SATA or M2) it can lead to data loss if they get no power for a long time, with an HDD this is not the case because they are magnetically stored and read.