I would probably go with the smallest battery monitor you could find. It could be digital.
There just isn't much room in the switch panel box. I wish I had a few more switches.
You might even look for a combination switch panel/battery monitor. The one pictured below isn't suitable, but gives you an idea. Maybe they make a small one with only 2-3 switches that could be mounted next to the other switch panel. Even if you dont need the extra switches now, you might in the future.
![]()