CyberPower’s CP900AVR has a simple-to-use interface with just two buttons (electric power on/off and mute) and 4 indicator lights (showing if the device is turned on, in the event the battery backup kicks in, when AVR is activated, and when there’s an influence overload) within the front with the device. https://elliottefecc.imblogs.net/85932759/a-secret-weapon-for-ups-battery-tester