Can surefly and e-mag both be on one engine without backup battery?

[Will.iam]

This is for the A&P’s and AI’s out there, 

surefly requires a secondary backup battery or mag in case of complete electrical failure (per their STC) but since the e-mag has its own generator in case of complete electrical failure, could i install an e-mag where my mag is now and enjoy the benefits of dual electronic ignition for better fuel efficiency, get rid of my one mag 500hr overhaul check, and remove the added weight hassle and install time and cost a backup battery would require? I also kind of like the idea of having two different ignition systems so that if there is a design failure it would not take out both systems. I. E. Dual  GI275 both going into airborne alignment which in weather could make that a single point of failure. Is this possible? If i didn’t already have the surefly, i could have gone with dual E-mags but they were not available at the time i got the surefly. 

[Hank]

I'd be careful with that. I've had two total electrical failures in flight (2010, 2025), and in neither of them was i worried about finding a place to land.

The first one was just below the clouds, crossing the VOR inbound ~1000agl over the WV hills, nowhere to land but the airport 8 miles or so away. Not a place to lose ignition . . . .

[Ragsf15e]

1 hour ago, Will.iam said:

This is for the A&P’s and AI’s out there, 

surefly requires a secondary backup battery or mag in case of complete electrical failure (per their STC) but since the e-mag has its own generator in case of complete electrical failure, could i install an e-mag where my mag is now and enjoy the benefits of dual electronic ignition for better fuel efficiency, get rid of my one mag 500hr overhaul check, and remove the added weight hassle and install time and cost a backup battery would require? I also kind of like the idea of having two different ignition systems so that if there is a design failure it would not take out both systems. I. E. Dual  GI275 both going into airborne alignment which in weather could make that a single point of failure. Is this possible? If i didn’t already have the surefly, i could have gone with dual E-mags but they were not available at the time i got the surefly. 

I thought the “e-mag” is only for experimental?

[Will.iam]

11 hours ago, Ragsf15e said:

I thought the “e-mag” is only for experimental?

You are so correct. That would be the flaw in this setup but apparently not for long or however long it takes for approval:

as of July 2025, Hartzell Engine Technologies acquired E-MAG, and certified versions for standard-category (FAA-certified) aircraft are in development as PMA-approved products for dual installations. These are expected to become available soon, expanding beyond experimental and Light Sport use. Until then, E-Mag remains exclusive to experimental setups.

[DXB]

43 minutes ago, Will.iam said:

You are so correct. That would be the flaw in this setup but apparently not for long or however long it takes for approval:

as of July 2025, Hartzell Engine Technologies acquired E-MAG, and certified versions for standard-category (FAA-certified) aircraft are in development as PMA-approved products for dual installations. These are expected to become available soon, expanding beyond experimental and Light Sport use. Until then, E-Mag remains exclusive to experimental setups.

Certification for the E-mag has been a year or two away for more than a decade. Maybe Hartzell's acquision of E-mag provides a real possibility of it now, but these timelines are always much slower than billed across aviation.   

[Justin Schmidt]

Soon in aviation is 30 or so years