G3X Battery Backup

[vasrv7a]

I am planning to upgrade my VFR panel to IFR using 2 Garmin G3X displays and a Dynon D10A as a backup. I currently have 2 alternators (1-40amp and 1-20amp backup), and I will have the D10A configured with an internal battery. Since the G3X units do not have internal batteries (they only have what Garmin calls "dual isolated power inputs"), is anyone who has, or is planning to install multiple G3X displays planning to install a TCW battery backup instead of, or in addition to a backup alternator like I have now? What are others doing to sustain reliability of thier all glass IFR panels?

Thanx.

Victor

[KPmarc]

I have the TCW iBBS in my airplane and it's been very good. With two GDU screens running full brightness and the GSU (AHRS, etc) online, I get right around 90 minutes' use on the backup. The G3X two-screen is supposed to use about 3-3.5 amps max, but it looks like it's usefully less than that once the system is running.

TCW has an excellent product and superb support.

[vasrv7a]

Marc,

Thank you for your reply... Do you have just one alternator?

Thanx.

Victor

[KPmarc]

Yes. B&C 60-amp, plus an Odyssey PC-925. This is a Glastar Sportsman, not an RV. I'm using the big battery to ballast the IO-390 up front.

I feel completely comfortable with an all-electric airplane as long as the backup battery system is well isolated, and the TCW system is.

[milestogo]

I'm going with the same setup as Marc in my Sportsman (dual G3X, TCW, B&C 60 AMP alternator). adding a TruTrak ADI with its own backup battery and GPS as well.