Electronic Ignition: Two alternators or two batteries

[Davea320]

As far as the electrical system ; I?m considering EFII

Dave

[Waiex-guy]

Or you left something (maybe master?) ON. Nice to have a second try if you are somewhere remote, or just want to get going.

[rongawer]

Originally Posted by tracy

One battery, one alternator, one electronic ignition, and one engine. A man’s man.

Ooh Rah. Just be sure to have that extra hand held radio so you can say "mayday, mayday, mayday" and inform others of your plight come the event one of those fail.

Personally, I do two batteries with the second battery on a separate emergency bus, which has a voltage maintainer circuit and monitoring on the EFIS. If both my alternator and main battery actually fail at the same time (consider the odds of that compared to the average 500 hour MTBF of a magneto set), then a flip of a switch provides me 1.5 hours to find a place to land before voltage drops below 11.8 volts. {tested}.

[tracy]

Got it! So when that one engine fails, you have all your radios to scream mayday. Wait....no...you would be in the same boat as me.

[rongawer]

You nailed it.

For the record, I always carry my handheld radio...because I no longer fly a twin.