=> Whenever I plug my MBP into a Inverter & battery based power supply any action done on the MBP brings reactions from the power supply in the form of fluctuations. My MBP also has the slight shock effect when I use it while plugged into the mains. I can feel it if the MBP is charging and I drag my finger over the closed lid. But the problem that I outlined in the beginning was noticed just a few days ago. When the power goes out, the Inverter + Battery based backup gets activated. If the MBP is plugged in while this happens, any major change in the display - change spaces, open tab, close tab - brings out a significant dimming in the lights around the house. It only dims for as long as the display is changing ( a few ms). The voltage is obviously fluctuating. Why does this occur?