^ second vote for the battery alert package. Works brilliantly. I slimmed it down a bit for my setup, but the general principle remains the same. @NotoriousBDG has done a great job there.
Any chance you could share your “slimmed down” setup? I too am using the package. I do not use the groups or the Mqtt discovery. Just the automations. Works great except it tracks my cell phone batteries. I used battery_alert_disabled: true In my customize settings for all cell phones but it still alerts on them. Trying to figure out a way to fix that portion.