My semi average spinner got through 4mm hardox steel at less than 50% throttle, stainless steel would be like tissue paper. In fact, I can't link the video but search 'HardWired 2 vs Shard vs Shiny vs Satanix vs Cannon Fodder' on YouTube, my top panel was stainless on HW2 and Shard totalled it in a single hit...

And yeah you need battery powered things, mains voltage is too far off to use. If you buy two mains angle grinders for it, they flat out will not work...