The skeleton architecture was Z-13/8 All Electric Airplane on a Budget with P-Mags, with the following modifications: Z-25. SD-8 Auxiliary Alternator Installation (with Self-Excitation Feature).
Z-33. Maintenance / Hand Prop Option for E-Mags/P-Mags.
Z-32. Heavy Duty E-Bus Feed.
AEC Website: Starter (with) Run-On Relay.
Z-14. Dual Battery, Dual Alternator, Split Bus, (for LR-3 Alternator Controller wiring only.) 15A in-line fuse installed at SD-8 Alternator, and Alternator Warning lamp connected to NC terminal of relay, per B&C instructions.
All ammeter shunts deleted.
Low voltage warning via Grand Rapids Technologies EIS Model 4000. I'm one of those weird people who insist on having an avionics master switch. I simply do not know whether all of the electronics in my airplane, initially or eventually, will be tolerant of voltage oscillation during starting (and I don't want to find out by the trial-by-fire method) so I feel better simply leaving them de-energized until the engine is purring. Since my instrument panel is a fairly simple all-electric day/night VFR (except for conventional backup ASI and ALT gages), the Endurance Bus is essentially the "Electronics Bus" as well. In the event of a main alternator failure, the back-up alternator will carry all the electronic loads without breathing hard. For these reasons, I've elected to install a slightly expanded "Avionics Bus" and call it a "Heavy Duty E/E Bus." E/E stands for Electronics/ Endurance. Here is the worst case scenario for Endurance operations:
| | Load | Amperes | |
| | Left P-Mag (if internal power fails) | 0.5 | (Battery Bus) | | Right P-Mag (if internal power fails) | 0.5 | (Battery Bus) | | 2 Mitchell fuel gages | 0.0 | (Battery Bus) | | Electroluminescent panel & LED dome lighting | 0.5 | (E/E Bus) | | Intercom PS-1000 | 0.25 | (E/E Bus) | | Transponder KT-76A | 1.5 | (E/E Bus) | | Encoder | 0.2 | (E/E Bus) | | Dynon D10A EFIS | 0.8 | (E/E Bus) | | Grand Rapids Tech. EIS Model 4000 | 0.15 | (E/E Bus) | | Battery Contactor | 1.0 | | | Com Radio Icom A-200 (RX) | 0.6 | (E/E Bus) | | PDA/GPS HP x4705/Teletype Bluetooth | 0.5 | (E/E Bus) |
| | Total: | 6.5A |
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Obviously, if the back-up alternator failed and the battery had to carry the Endurance load alone, the intercom, transponder and encoder, and Com radio loads could be shed, reducing the Endurance load to 3.95A or less.
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