If you have an APC UPS you may not, for whatever reason, want the OS to trigger a shutdown. The ‘apcupsd’ package will call shutdown whenever the battery capacity is reported too low. To prevent this, just edit the following file.
Edit /etc/apcupsd/apccontrol with your favourite editor. You should see something like this:
APCPID=/var/run/apcupsd.pid APCUPSD=/sbin/apcupsd SHUTDOWN=/sbin/shutdown SCRIPTSHELL=/bin/sh SCRIPTDIR=/etc/apcupsd WALL=wall
All you need to do is comment out the ‘WALL’ & ‘SHUTDOWN’ lines:
That should be all that’s required.