A whole hour of runtime would be mean 1C discharge. 80V (which is likely 72V, but in the US it's ok to label the max voltage rather than the actual one) is made

A whole hour of runtime would be mean 1C discharge. 80V (which is likely 72V, but in the US it's ok to label the max voltage rather than the actual one) is made of 20 Li-Ion batteries in series. Lets say 2 in parallel, so total 40 batteries. I'd go with 3Ah per battery (could be more for 21700) and around 2Kgs weight. For 1h work that's ~430W of power which is rather under powered. That fast charger (say 30min to charge) for this thing would be quite a thing to witness with over a kW of power draw. About Stihl, it uses a 36V battery, so 10 Li-Ion in series. Which is half as powerful. I can't see a capacity higher than 36V/6Ah from Stihl. Now, it possibly uses multiple batteries, however, the issue with charging still remains the same. Running a generator would be louder than the device, so imo that's a moot point. I'd consider using a massive power bank and/or lots of pre-charged batteries to carry the day but not an inverter.Taking enough batteries to swap and charging them in off-hours seems the only sensible approach (albeit not cheap)