This exact thing happens to me, I've tried using APC, Tripp-lite, and CyberPower. The laser printer (not directly attached to UPS) but on same circuit warms up the fuser thus causing a brown-out condition on the circuit, then causing the UPS to activate to hold up the PC and other devices.. thus cycling its sealed lead acid 6v battery within a few seconds, causing them to go below 50%. This may work a few times but if it drops below 50% charge it damages the 6v battery.. thus will need to be replaced continually unless you move the laser printer or have the circuit conditioned to handle the greater load.

This exact thing happens to me, I've tried using APC, Tripp-lite, and CyberPower. The laser printer (not directly attached to UPS) but on same circuit warms up the fuser thus causing a brown-out condition on the circuit, then causing the UPS to activate to hold up the PC and other devices.. thus cycling its sealed lead acid 6v battery within a few seconds, causing them to go below 50%. This may work a few times but if it drops below 50% charge it damages the 6v battery.. thus will need to be replaced continually unless you move the laser printer or have the circuit conditioned to handle the greater load.