EFII Amp Draw

Has anyone got any good numbers on how many AMPS a single ECU and Coil draws at peak. Im trying to figure out my backup source of power and leaning towards a TCW battery (3 AMP hours version). I like this approach because of the automatic switching it offers should I have an issue with the main source of power. I know that EFII claims 1.1 AMPS at 2500 RPM but I was looking for in the field numbers out there since the ECU requires a 5 AMP breaker and the coils require 10 AMPS. Thanks a ton ahead of time for any info.

Are you also using the fuel injection portion? If so you'll also have to account for a fuel pump. The SDS EM-5 install says:

Current draw of the pump, ECU, injectors and coils would be around 7.5 to 10 amps. An 8 amp/hour battery should give you a solid 30 minutes of flight time, just running the engine electrics. An 18 amp/hour one, around 1 hour. We want to be able to sustain at least 10 volts to the electrics.

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I'm curious given the weight, wiring complexity and cost why more folks don't opt for a secondary alternator, B&C for example?

I installed the second B&C alternator, 30 amps. I also have a second EarthX battery.

219PB said:

I installed the second B&C alternator, 30 amps. I also have a second EarthX battery.

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That is my plan as well. I'm planning to eventually be IFR capable, so I wanted that redundancy. I figure it would also give me enough redundancy that I could fly day VFR with one battery or one alternator inop, at least to get back home.

I can probably get a good estimate on my next flight if I remember.

My EBUS/Batt Bus pulls about 7 amps with a full dual EFII ignition no fuel, dual screen G3X and a MidContinent SAM backup EFIS. The Aeroelectric Z-13 with the SD8 worked as advertised, It made my real main alt failure a non-event on a long cross country.

No fuel injection, just a dual ignition of which I'm trying to use a tcw 3 amh backup battery to give me enough juice to find a surface to land on. Thanks Crabandy, I followed Z-13 as best I could but I also went with the EFII bat bus option. I just want something to automatically kick in should the bat bus and the backup alt fail.

EIGN-4-1 current draw

Hi Luis,
The EIGN-4-1 system draws an average current of 1.2A at high rpm.
The breaker values are short circuit protection.

Robert