Position light and battery upgrades and fixes

[chanik]

I've finished all the electrical tweeks I wanted on my CTSW so I figured I would list them out. The only mechanical change I made was the Matcos and monster retread tires (much nicer). When I got my plane, the battery was always depleted, the blindingly bright voltage warning light would come on if I ran the landing light, there was substantial noise in my ANR headsets. It wasn't good. Much of these are described elsewhere in this forum so I'll summarize here and most of which can be seen in this picture: http://www.johnea.ne...rt/P1020211.JPG

1. Add a diode to the feedback on the Ducati regulator. This pushed my charging voltage from 12.9V (much too low) to 13.7V. 13.9 would have been ideal but 13.7 is close enough. Roger looked at this on other birds and sometimes it is fine, sometimes it is ~1/2V low and some are like mine, very low. The ~13.4V systems would benefit from a Schottkey diode instead on the PIN diode (0.8V) that I used.
    
   
2. Switch to LED landing/Taxi light. The AEON V5 Aurora bulbs were the best I could see online but they are still too wide at 30 deg, not well sealed and only 7W (450Lm). So I finally made my own 15deg MR16 bulb for 25W and ~2700Lm which makes it twice as bright as the halogen bulb it displaced
    
   
3. Replace the Odyssey with a LiFeP battery. That saves me 4 lbs, has better cold cranking and capacity and should last 2-3x as long cycle life. $160 LFX18 series from Shorai. I made a new fiberglass battery box rather than hack the existing box as it did not fit exactly.
    
   
4. Replace the way too little capacitor. Rotax calls for a 22mF, 25V cap minimum and bare minimum is a better description of it. The one FD uses is an HA series. the internal resistance is fairly high so it is only rated to 4.3Amps of ripple which would easily be exceeded if the battery went open circuit. With all the lights running, you would have 3x its rated ripple current and it would overheat and fail in short order. You would hear it too. They go off like little sticks of dynamite. Replaced with a 100mF monster. , http://capacitoredge...=ALS40A104KF025 16+ amps rated ripple and >2x the rated life. Size matters in caps. As you can see, this one is big. One nice side effect, all the noise is gone. I tried my new aveo lights jury rigged to a cig ligher plug and the LED switcher landing light and everything else on. Whisper quiet in the headsets.
    
   
5. Aveo UltraLP postion/strobe lights. http://aircraftprodu...ave-wpstg-r-403 The german ones are fading and not very bright to begin with. One of the green strings is gone out too. These new monsters draw 400mA for the color/ rear-facing white and 3.0Amps pulsed when they are strobing for an average of 800mA each total current. Bobby Cau had a problem with these big current pulses with his plane. But they are truly blinding. Will install them as soon as the rain and cold subside a bit.
   

That's about all I can think of to fiddle with. I'm E-LSA but of these changes, #1 would be dubious without an LOA. It's a tiny change but you are still changing the wiring. #2 is fine since no wiring is changed or added and FD doesn't specify anything specific WRT landing bulbs. #3 is certainly in need of an LOA as FD does specifically describe acceptable batteries. Worth getting though. Much nicer battery. #4 is allowed since ROTAX just specifies the cap as a 22mF minimum. They really should have tightened up this spec since there are, in fact, worse 22mF caps that could be used here with even lower ripple current ratings. #5 should have an LOA since it is a significant change from their specified parts.

[chanik]

OK, try this one and search it on digikey. Changed above too. It's a big $27 cap ALS40A104KF025

[FastEddieB]

Let me know how that lithium ion battery works out for you.

 

The Odyssey PC680 in my Sky Arrow weighs about 15 lbs. The #LFX18L1-BS12 replacement shows at about 2 lb.

 

As weight-limited as I am, I would love the extra 13 lbs of extra load - about 2 extra gallons!

[FredG]

Kurt, sent you pm regarding wheels you have for sale. Or, reply to me at fredgerr@yahoo.com. Thx. Fred (sorry to hijack thread)

[Roger Lee]

Hi Kurt,

 

That is a big capacitor in size. Where did you mount it? On the firewall? (105mm L x 51mm W)

[chanik]

The battery is holding up fine. Cranks better than the Odyssey PC310. Bear in mind, Shorai's A-hr equivalent rating is a contrived thing. If you had to rely on it in the case of a failed generator, then you would see ~84W-hr or about 1.5hr running the Dynons, radios, Xpndr and GPS. The PC310 if new would be just 20% less energy. The only achilles heal is you can't let it drop below 13V for long or it will be ruined. So I leave the solar charger on it to be safe. Turns out the CT still draws 3.5mA with everything off, or about 1W-hr per day. In two month of non-operation, the battery would be depleted and start to self-destruct.

 

As for the cap, I mount it to the box frame in the front as you can see in the picture. The little cap was in the same spot behind the frame. I used a pair of ty-wraps and some silicone RTV to keep it locked in place. It barely fits. I can see there is much variability in what other OEMs use in caps for the 912. The FD choice is too dinky but that is mainly ROTAX's fault for not specifying the cap better.

[Doug G.]

Where are the 3.5mA going?

[chanik]

Where are the 3.5mA going?

That's a good question. I don't know. With all the switches off, it should be more like 0.1mA just due to various leakage paths.

[Doug G.]

Pulling the breakers one at a time doesn't work to find it? It is a good thing I keep mine on a charger or in our weather I would have a frozen battery...or maybe that doesn't happen to AGM batteries?

[Jim]

If you have a Dynon EMS120 with the current shunt, I think it draws about that much. I considered adding a relay that would disconnect the shunt sense leads when the power to the Dynon went away, but then figured it wasn't worth the trouble. I fly enough during the summer and keep the plane on a trickle charger in the winter.

 

Pulling the breaker to the Dynon won't cause this load to go away.

[Roger Lee]

Hi Kurt,

 

That's pretty much what I have seen for draw here in Tucson. It seems to be perfectly normal with some setups.

If you only have analog gauges you won't have the drain. If you have Dynon with the shunt then you will have it. We tested 3-4 planes here and that's the way it pretty much bares out. If you fly 1-2 every 3 weeks you shouldn't have an issue. I have 6 CT's at my field and only one puts his on a charger.

[chanik]

If the EMS120 current sense shunt is on the high side, the +battery connection, then this would be leakage through the shunt amplifiers to ground when they are powered down. Dynon likely have a 3-4K opamp input impedance so that allows the 3.5mA to leak through the protection diodes on the chip inputs. That's likely it because there are few other places it could go. The Ducati regulator is a reliable open circuit to the battery

[Jim]

Exactly. I never know how much detail to go into.

[Doug G.]

:-) Roger, I deal with -10 or -15F at night (sometimes colder) plus some days in single digit highs. (I don't usually fly then.) The last thing I want is a frozen battery. One cell gone in a regular car battery and you throw it out. I don't know if AGM changes that, but my charger stays on in the winter. My density altitude the other day was -2300 ft.!

[Bobby CAU]

dear Chanik and Roger,

this is very good article for me, i passed to my friends in Australia as well.

 

recently, i always having some issue with my alternator (according to some friends from Australia)

during flight, as we know my fully glass cockpit CTSW using a lot of power and more with my new AVEO 6 in 1 strobe (even LED), transponder, and radio also sucks much energy from the battery.

 

it seems my alternator cant keept much backup power for my usage or my battery cant recharge quick compare to my usage, then during approach most of the time the flap will be jam a while then after i increase the rpm will be start to normal again ... when in hangar, im using CTEK just to keep the battery fresh.

 

do you have any idea about this ?.

[Safety Officer]

Our Rotax charging system.

 

The Rotax manual says it is a 20A system, but its peak really is 18A and its continuous is 16A. FD with all its components and especially if you add anything can be at the limit depending on what you have on at a specific time. Be careful what you add to your system and learn to turn off things that aren't actually needed.

[Bobby CAU]

Our Rotax charging system.

 

The Rotax manual says it is a 20A system, but its peak really is 18A and its continuous is 16A. FD with all its components and especially if you add anything can be at the limit depending on what you have on at a specific time. Be careful what you add to your system and learn to turn off things that aren't actually needed.

 

what should turn off during the flight?.

landing light?. or what?.

 

any advise?

[Roger Lee]

Hi Bobby,

 

What you turn off is up to you, but lights and any cockpit items that are more or less superfluous can be turned off. I only use my Dynon D100, D120 and my GPS, radio and transponder.

What you really need to do is take a look at each item you usually have on and find out what the current draw is. That will go a long ways in seeing what your over all current draw is.

 

Part of the problem is FD keeps adding more and more electrical items and some have bigger current draws than what the SW's had. Then the owner comes along and adds even more electrical draw with their fun electronics. Remember the system really isn't a continuous 20A system.

[Doug G.]

And, the AIM now recommends using all our exterior lights when taxiing, lined up at the runway, taking off, and below 10,000 ft. Which means all of us nearly all the time (in the US anyway). This is a recommendation though, not a legal requirement. (2013 AIM 4-3-23)

[Bobby CAU]

i just do additional AVEO 3 in 1 for my strobes only, the rest still the same for the changes.

im using GPS bendix, Dynon D100 and D120, radio and transponder. thats all.

 

i will keep my strobes and landing light on all the time. (is this wrong?)

 

but it seems the reading on my EMS for the battery always up and down.

regarding my battery, during cruising with rpm 4600-4800 volts in my EMS showed increase 2volts from 11volts or 10volts sometimes and when i did the radio it will became minus another 2volts.

it seems, my battery not recharging enough and keep the backup power for my usage. FYI, my CTSW is come with full glass cockpit.

many times during approach when i need to do decreasing the rpm or idle, flaps will be jam and for a while and will be comes back after i put more rpm and this is really interrupt my focus.

[Roger Lee]

Many of us don't use our lights because they are too hard to see any way. You need to be within 50-100 yds. To see them. If it is bright outside here in Tucson it's even worse. The LS has a much better position light that you can actually see. I don't use mine at all on bright days. If they were better lights it might be different or if the outside light was low. I can't usually see other aircraft either unless I'm close.

[Bobby CAU]

Ok and thanks Roger,

i would try to fly with strobes and landing light off this time and see if i still have my flaps jam.

 

i acknowledge the biggest power consumption is from radio, am i right?.

and during my flight, i will use a lot as well (some friends in tower say hello or traffic is others friends too).

[Roger Lee]

Hi Bobby,

 

I'm sure it isn't any one thing, but an accumulation of electronics.

[chanik]

The huge draw is the landing light (90W). The Dynons, Xpndr, radio and GPS usually add up to only 65W. The Aveo lights are 10W each with postion and stobe. So you really cannot afford to run the halogen landing light all the time with the anemic rotax charging system. That is one reason I switched to the 25W LED based landing light. Incidently, it was your problems with noise from the AVEO strobes that got me working on the electrical noise problem and ultimately to the need for the big 100000uF cap.

[Bobby CAU]

hi Kurt,

thanks for response me.

 

i will try now to off the landing light then.

for AVEO strobes, i clean the ground last month and it seems the pulse noise quite low now.