I've wanted to implement something like that with my 1920R UPS for my rack but haven't found the time to commit to antiquated hardware.
Was enough of a hassle dealing with the expired SSL certs on the management card yet getting software running on one of my machines to communicate with the UPS.
All things considered my two servers chilling chew around 60w on average, not taking into account my POE cameras or other devices. The UPS should run for over a day without getting close to draining its batteries (have a half populated ebm too).