How to solve the problem of writing large files to the Agestar USB box?

Question

Hard disks

Faced such a problem: there is an external USB "box" model 3ub3a7 for backing up the contents of the computer. It works flawlessly, but when trying to overwrite files of about 100 GB and above, it randomly gives an error. Maybe at the very beginning, maybe at the end. Tried to limit the write speed (through the total commander) does not help.
What could be the reason? Advise a reliable and not very expensive device for such purposes (2-3 terabytes are needed).

Answer 1

I seem to understand what the problem was. Specially put the movie on viewing located on the disk from which the file was copied and everything was successfully copied. Apparently, the box is not at all to blame, it was the system that stopped the disk spindle, because. considered it unused. Let me remind you that Total Commander and its directory synchronization tool were used for backup.

Answer 2

For backups and large files, I move away from external drives.
I'm going (already soldered) to put a paired toggle switch with a SATA power light on the front panel 5.25, connect the disk to the SATA port with hot plug enabled.
It is necessary - turned it on, reset the data, "Safely Remove", turned it off.