Unlike the PFA, which could be run off a small 12V battery, the IFA only seems to support phantom power. This change is quite understandable, given the fact that the relatively weak battery has always been the IPA's achilles heel. In fact, I stopped using my IPA after it dropped out during the second to last song of a The Cure concert. Without that hiccup, this would have been one of my best recordings ever.
The fact that Naiant now doesn't seem to have a battery-powered solution for running active mics anymore is a great loss to our community.