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RV12-iS Low Battery Amps with Landing Lights

Rotax alternator capacity is borderline anemic. Perhaps your flights aren’t long enough duration to restore battery after engine start and ground ops at low engine speed.

You might want to consider leaving battery on charger during off-operations. I use an Odyssey 6 Amp Portable Charger which I leave connected to the airplane all the time in the hanger. The Odyssey charger is not a float or trickle charger – it is designed specifically for Absorbed Glass Mat (AGM) and flooded lead acid batteries. The charger maintains voltage only as needed, so when the battery is fully charged there is no current flow. The charger has an automatic cycle that disulfates the battery once/month. This cycle also happens every time the charger is reconnected after flying.

Install a pigtail connector near the oil access door for quick connect to charger. See photo below.

I’ve been doing this for two years and battery loves me...

 
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Depends which motor the OP has. The 912iS has two generators with plenty of capacity.
 
The charging system is not working right.
Voltage of the electrical system should be over 14 volts.
What is it?
 
My Sling 2, has the 912 ULS. I?m running dual G3x?s, G5, Garmin radio, autopilot and LED landing, taxi and anti collision lighting. I was worried the internal alternator would be overwhelmed and almost sprung for the aux alternator that the iS has, but the factory assured me I?d have no problem with power and to date, I haven?t.

To the OP, I?d start looking at the voltage regulator and the External alternator. Best of luck on the -12iS.
 
To the OP: I am currently troubleshooting the same scenario. Can you describe what the correction was to your situation? Thank you!
 
I flew for nearly a hundred hours dealing with my charging system barely keeping up with the loads. Then it stopped altogether. I landed with the emergency battery on and every strobe flash dimming the glass panel. This turned out to be the stator had fried. There is a small oil passage or ‘jet’ into the hollow back of the crankshaft that had become plugged, taking the cooling away from the stator. It is so small, it had to be cleared with the smallest safety wire I had- I think 0.020. Filled with grey slime/sludge. New stator installed, old one with heat-fried wires removed. Problem solved, for now. I had been changing oil at fifty hours with use of decalin. I now change the oil as much as possible and clean the oil tank every oil change. I try to be super careful not to leave any rag lent in the tank for fear that any small particles can clog that oil jet.
I hope this isn’t what is happening to your iS as it is not a small job. And it seems likely something else is going on as the low hours on your engine point to maybe not having the kind of build up of slime that mine had at six hundred hours.

Headwind
 
I flew for nearly a hundred hours dealing with my charging system barely keeping up with the loads. Then it stopped altogether. I landed with the emergency battery on and every strobe flash dimming the glass panel. This turned out to be the stator had fried. There is a small oil passage or ‘jet’ into the hollow back of the crankshaft that had become plugged, taking the cooling away from the stator. It is so small, it had to be cleared with the smallest safety wire I had- I think 0.020. Filled with grey slime/sludge. New stator installed, old one with heat-fried wires removed. Problem solved, for now. I had been changing oil at fifty hours with use of decalin. I now change the oil as much as possible and clean the oil tank every oil change. I try to be super careful not to leave any rag lent in the tank for fear that any small particles can clog that oil jet.
I hope this isn’t what is happening to your iS as it is not a small job. And it seems likely something else is going on as the low hours on your engine point to maybe not having the kind of build up of slime that mine had at six hundred hours.

Headwind
R

Consider running premium Mogas and that problem should be alleviated. Rotax has been building all their engines, aircraft and otherwise, to European fuel standards for running exclusively on Unleaded Mogas with 91 RON octane or better North American premium gasoline.
 
Oh, I'm trying to be religious about using MoGas, now... I'm also trying to use the airplane to it's full travelling machine potential- I often am nowhere near MoGas and have to use the AvGas available.

HW
 
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