Is plunging in an ESD strap to a batter backup like a UPS or APC reasonable? I have a simple ESD cable that terminated in a 3 prong wall outlet where only the earth ground prong is metal. There is a 1MEG ohm resistor between the contact on the strap and the earth ground prong. Will the strap discharge me to earth ground through the backup? Is there a way to tell if power strips are isolated from earth ground?