In the last year I have exchanged email with both an EX owner and an FX-3 owner who believed the emergency ignition test should be run with the "mag" switch in the Both position. With the switch on Both, the Left ignition system will contine to run the engine at normal speed even if the emergency Right system is inoperative.

The emergency ignition test should be run with the "mag" switch in the RIGHT position so only the right ignition module is in use AND it is powered by the emergency ignition battery.

I like to stay in the emergency position for about 10 seconds and to monitor the emergency ignition battery voltage. The rate of voltage decay, and the voltage after 10 seconds, are good indicators of the condition of the emergency ignition battery.

AFM rev B checklist specifies -

Electronic Ignition....... Check for alternating fault lights
and no roughness. Little to no RPM drop should be noted
 Backup Battery (if installed)......Key: R, EMERGENCY
Engine runs same
Amber light illuminates
NORMAL, key: BOTH

The G3X supplement includes additional detail:

9.4.4 BEFORE TAKEOFF
 Brakes .................................................. ................. Hold
 Throttle.......................................... ............. 2,000 RPM*
 Ignition.......................................... ........................ Right
G3X L.IGN OFF (red)
Left Ignition Light illuminated
Insignificant RPM drop
No Roughness
 Ignition.......................................... ...........................Left
G3X R.IGN OFF (red)
Right Ignition Light illuminated
Insignificant RPM drop
No Roughness
 Backup Battery
o Ignition.......................................... .................. Right
G3X L.IGN OFF (red)
Left Ignition Light illuminated
o Backup Battery......................................Emerg ency
G3X IGN BACKUP (yellow)
Insignificant RPM drop
No Roughness
o Backup Battery........................................... .Normal
 Ignition.......................................... ......................... Both
Verify G3X Indications Extinguished

This seem to be unchanged from rev NC so I don't understand why there is any confusion. The emergency ignition battery will give about 30 minutes of flight if it is in good condition. It seems prudent to test it properly.

I'm not picking on the two people I know were doing it wrong. Just hope this message gets to anyone else that may be running the test with BOTH selected.