Hi!
my APC UPS is giving up the ghost (internal fault) and just did a quick browse and spotted this.
Powercool
would it be compatible with NUT?
Are you sure? Nominal is named voltage, which for 2 12V in series would be 24, and the voltage low needs to be the tested value just before the UPS powers down with a low battery condition. You can't just put a value in and assume it's correct. Either get the official value from the manufacturer, or test it.