I would prefer that apmd log 10% increments not 20. And fix the off by one, which made it 21. (I find it odd to see a sequence of 99, 78, 57% in logs.)
Index: apmd.c =================================================================== RCS file: /cvs/src/usr.sbin/apmd/apmd.c,v retrieving revision 1.75 diff -u -p -r1.75 apmd.c --- apmd.c 6 Feb 2015 08:16:50 -0000 1.75 +++ apmd.c 28 Aug 2015 04:28:03 -0000 @@ -153,7 +153,7 @@ power_status(int fd, int force, struct a bstate.ac_state != last.ac_state || bstate.battery_state != last.battery_state || (bstate.minutes_left && bstate.minutes_left < 15) || - abs(bstate.battery_life - last.battery_life) > 20) { + abs(bstate.battery_life - last.battery_life) >= 10) { #ifdef __powerpc__ /* * When the battery is charging, the estimated life