What is the net output of Rotax's internal generator?

James Ott wrote:

I do exactly the same Roger. I was wondering if I am overkilling it, but glad to hear from a pro like you.

Hi James,

There is nothing wrong with being a cut above average. Information, education and documentation is key to being above average and better prepared for life and what it brings with it. It's not up to you to slow down and let people catch up. It's up to them to speed up and keep up.

Life gets harder and not as much fun when you let things happen vs making them happen. ?

Help please....

I have a 2004 912ULS in an Evektor Sportstar. I had trouble starting, flat battery. i put some charge into the battery, not fully charged but with a three hour three hour flight ahead I expected it to recharge while flying. I was wrong it went completely flat 10v.

The red generator light comes on with ignition and goes out once started as you expect however there's absolutely no charge. 9.8v at 3000rpm.

Any suggestions where to look for the fault?

Phil

Your battery may have a bad cell. Even if the battery isn't very old you may need a new one.

Thanks Roger,

The first time it went flat I was at the airport 600km from home. I dropped it at the door of Northam Air Services with a note asking for it to be charged. When I picked it up more than a month later it cranked the engine as if fully charged. That indicates the battery charges and holds a charge ok.

What I didn't realise is that every time I got into the plane I was using up the battery charge without knowing it. The Sportstar only has a charge light, no volt meter and no amp meter. Last time I flew for nearly three hours and parked the plane. The battery was most likely depleted at that time, I had no way of knowing.

When coming home this time I started out with a small charge in the battery counting on it recharging during the first 2hr leg. It didn't, I had to reach up through the bottom of the cowl and attach a jump starter and then pulled it off once started. During the next hour of flight the tacho dropped out so I switched off the power to the iPhone and iPad, nav lights and beacon. The tacho started again. Shortly after the iPad with OzRunways went flat so I connected it to the power supply again but lost the tacho. I was already at 6500' on cruise so didn't need instruments but I still needed navigation.

Tonight the battery has been on charge for 10hrs and is showing 14.7v so looking good. I'll do a load test tomorrow but I don't think I have a battery problem. It's a one year old Odyssey AGM.

Phil

Odyssey batteries are okay, but over the last few years I have found Earth-X much better. The Odyssey is a 12v and 100 CCA. The Earth-X is 13.2v and 320 CCA.

If your battery isn't charging in flight then you need to diagnose the voltage regulator to make sure it's sending a charge to the battery.

Voltage: 13.2
Weight: 4.1lbs (1.86kg)
Cold Cranking Amps (CCA): 320
Peak Cranking Amps (PCA): 680
Amp Hour (1C Rate): 12.4
Chemistry: Lithium Iron Phosphate (LiFePO4)
Case Size: E
Dimensions: 6.5" L x 3" W x 6.6" H
                    (166mm L x 76mm W x 168mm H)