Batteries give an exceptionally flat DC power supply....,..But getting it to a usable voltage for your equipment (AC or DC) is the tricky part. Most transformers / inverters rely on some kind of switching circuit that messes up the "pure" current you started with.
Just because an inverter says pure sine wave doesn’t mean that it is and a true "audiophile" grade inverter (if they even make then) will be extremely expensive. Which model are you using? Did you research what the sine waves really like like on an oscilloscope?
PS. I know there are many things people claim to hear that can not be measured by state of the art equipment. But power coming in is not one of them. The DC voltage is either perfectly flat or its not. And AC is a perfect sine wave with the proper voltage or its not. You can see this to the microvolt with the proper scope.
Just because an inverter says pure sine wave doesn’t mean that it is and a true "audiophile" grade inverter (if they even make then) will be extremely expensive. Which model are you using? Did you research what the sine waves really like like on an oscilloscope?
PS. I know there are many things people claim to hear that can not be measured by state of the art equipment. But power coming in is not one of them. The DC voltage is either perfectly flat or its not. And AC is a perfect sine wave with the proper voltage or its not. You can see this to the microvolt with the proper scope.