Battery discharge on new P2008 912iS Engine.

[lance]

My new Tecnam P2008 with 912iS and AirMaster CS Prop are running beautifully.

Today after 14 Flight Hours I noticed Battery is showing a 1 Amp discharge for first time  even though the Alternator is charging the battery

with its normal 9 to 10 Amps.

Lane A is 13.9 V and Lane B 13.9 V. Main Volts were at 13.8v at 5030 RPM in cruise.

Only one Pump  was on plus Garmin AP, Transponder & Radio + Strobe  & Landing Light.

I did not think to turn off some of these but will experiment next time.

I was on a 3 Leg Flight and  there was no discharge on Leg 1.

Leg 2 was very short so no photo of panel taken.

Leg 3 Battery discharge was noted and panel photographed.

Any suggestions please on what I should be checking next?

Thanks

Lance

[Flocker]

Maybe a faulty sensor?

[harley]

Lance, can you tell us what cruise speeds are you are getting with your AirMaster SC prop at what RPM?  I don't think we're allowed a CS prop with light sport here in the US.

[Flocker]

I'm seeing 117 TAS and 110 IAS on the pic. I need to convert LPH to GPH but I'm guessing it's close to 4.

[LSA Flyer]

I would check as many of the battery connections, alternator/voltage regulators you can reach for looseness. After that your idea of turning things off should go the other way: turn on both pumps, pitot heat and run the flaps; you should see a further increase in discharge. If the ampere draw is unchanged I'd look at the shunt for a bad/dirty connection or a blown fuse in the ammeter shunt circuit. If that all looks good, time to put a meter on things with the help of someone who can diagnose the charging circuit.


A side note, starting the engine with one pump is best for cranking but always fly with both on. Good luck, don't let anybody tear into replacing parts until you get a good diagnosis.
 
You could also remove the cover of the electric distribution box and push down on each of the many fuses. There have been reports of some not being seated fully and vibration backing them out. 

[lance]

Thanks for above information.
I contacted Rotax UK.
They provided Resistance figures for Lane A & B connector plugs.
We measured ours and OHM values were correct.

Another reply to follow.

[lance]

My LAME aircraft engineer explained that G3X is so accurate at measuring Battery Inputs and Outputs that G3X could have been
measuring a discharge as low as say 0.2 Amps but it would be displayed as 1 Amp discharge.

He has slightly reduced sensitivity of G3X measurements.

Engine data was downloaded via Rotax Buds and looked ok.
But a comprehensive download analysis cannot be done in Australia so still waiting for
results from Rotax UK.