Similarly to this question, I find that when a wireless mouse with low battery is plugged into a laptop running Ubuntu 18.04 on battery power, the screen automatically dims after 15 seconds of inactivity, even if the Power setting "Dim screen when inactive" is set to "Off". This doesn't make any sense to me - why would the dimming the screen help preserve power in the mouse?
15 seconds is very inconveniently short - how can I disable this automatic screen dimming? I do not have any power management programs like jupiter or tlp installed. This answer suggests running
gsettings set org.gnome.desktop.session idle-delay <seconds>
on the terminal, but that doesn't change anything for me. Disabling DPMS as suggested in this answer doesn't work either. The only thing that works is unplugging the mouse and restarting my computer, which is obviously kind of annoying.