I asked PC about putting a pure sine wave inverter in when they built my unit for that reason, but they only wanted to use the modified sine wave that they've been using all along, indicating that there haven't ever been any complaints about it. I didn't push the issue, and instead I got a nice adapter thingie so I could charge electronics from the dashboard when driving. Then, once I moved into my rig and started using stuff and sort of understanding how things work, I realized that the inverter would only be charging my computer (or phone or whatever) if I were not plugged in to shore power, but using the house battery. I usually am plugged in somewhere, so it is my understanding (and I may be waaaayyyyy wrong, in which case I welcome correction) that if I am plugged in to shore power or even using the generator, then even the inverter plugs won't be using the inverter, because it isn't needed then. It is only needed when using just your battery power. So when I did dry camp, I made sure my electronics were charged up ahead of time and if they needed charging while out there, I could use the adapter while driving or just take my chances with an occasional charge being done with the modified sine wave inverter. Sorry, that was way too long, and probably confused, and maybe wrong. But it's my two cents!
Carol, an inverter converts 12v to 115 volts. So if you are plugged in, or not, running generator or not, it's always running off the coach batteries