The FAA has clarified the upcoming ADS-B Out rules regarding aircraft without electrical systems, elaborating on the current FARs regarding transponders. The ADS-B rule, which takes effect on Jan. 1, 2020, to mandate position-reporting equipment in airspace where transponders are now required, will not apply to “aircraft originally certificated without an electrical system but which have subsequently had batteries or electric starters installed.”
Source: avwebFAA Clarifies ADS-B Mandate For Non-Electrical Aircraft