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Skyview Backup Battery Trickle Charging Test

larrynew

Well Known Member
I am able to charge my Skyview backup batteries with the system voltage BELOW 12.25v and the alternator/generator NOT online when trickle charging the battery.

I was concerned about having a fully charged Skyview backup battery while working on the avionics and before the first engine start. The Dynon installation manual states:

"To conserve your aircraft battery, the SV-BAT-320 is only charged with [sic] SkyView detects your alternator/generator to be online."

I also read a post here about the backup battery not charging when system voltage was below 12.25v.

So, I found that the backup battery will charge while on my Schumacher 1.5 amp trickle charger even though system voltage is below 12.25v. It took me about an hour to get from 9.95 to 10.54 volts on the backup battery and the system (battery) voltage only dropped a little. I did make sure everything was off except the one screen that was charging the battery.

IMG_2634.JPG
 
The SkyView does technically trickle charge any time it's on. The thing is, with a lithium-ion battery, voltage change from 9.95 to 10.54 volts is about 1% of the battery capacity. So it would take about another 99 hours (probably more) to fully charge that battery, instead of 2 when the SkyView above 12.25V. So we don't exactly consider it to be "charging". In fact, with a 30 second countdown timer, you would need to run SkyView about 1 hour after every power down just to recover the power used in the 30 second countdown.
 
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standby batteries

this is an area that Dynon needs to look at. If you are flying a lot, its great, but if you can't fly your airplane for a while the batteries go flat in the skyview and the D6.

I love my Dynon, but guys, this needs some work.
 
There is something wrong. The batteries should have well over half charge remaining after a year of not using them. If you don't fly the plane for a month, you'll be fully charged back up by the time your engine is warmed up.

Are you sure your batteries are still healthy? Have you let them charge all the way up (12+V on SkyView, 16.4+V on the D6) and measured how long they will run the instrument? Both should make it over an hour.

Also, what is your definition of "flat"? Lithium Ion batteries have funny voltage curves and if you think it's flat because it's down at 10.5V then you are actually still quite charged.
 
Battery test failed

I just tried the Skyview battery test tonight. The airplane battery (PC-680) has been mostly on the trickle charger over the last month, and the Dynon Skyview has been powered on sporadically here and there to run the engine 3 times (3 minutes each) and to configure the various electronics. Anyway, the test went dark at minute 23. The Skyview battery showed around 11.4 volts at the start of the test, so maybe it didn't have a full charge. Is there a way to determine if the battery is fully charged and ready for the 60 minute test?

Is this something I can ignore until I get more real, actual flight hours on the Skyview to have it charge up the EFIS battery? This weekend I could leave the trickle charger on and also turn on the Skyview just to charge the battery up all of the way.
 
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Bruce - you can check the status on the screen shown above - charging or charged. When I first tried to charge the back up with my charger, I made the mistake of not realizing I had to have the master on to charge the backup. I believe it can take up to 4 hours to fully charge. I could never make it through a test, but my battery was replaced under warranty - now it works great. I really wouldn't worry if not flying yet.
 
Why would anyone be interested in charging the Skyview battery at system voltages below 12.25? In real terms you are looking at a main battery that is already 40% discharged (generally considered Weak). I think the real point of running the system off a 1.5 amp trickle charger is the current limiting is reducing the voltage to the level of a nearly flat battery. The better answer is to get an adjustable DC power supply with adequate amperage and run it at 12.7 volts. Your Skyview battery will fully charge and pass the standby test with no problem.

John Salak
RV-12 #120126
 
I have two "cigarette lighter" outlets: one is wired to the main bus and the other directly to the battery (through 10A fuse). I plan to use the direct outlet to tickle charge the battery (master off) and the other to energize the main bus with a Radio Shack 13.8 V 19A power supply when I want to work with the skyviews in the hanger. This will also keep the skyview batteries charged. I think I will only use one outlet at a time.
 
To update this thread.

I got our SV-BAT-320 delivered last month and it tested at approx 10.5v. As I am not flying for a few months, I sourced a 12v lithium battery charger from fleabay which was for a heated motorcycle garment - checked output etc etc and it was OK. Worked a treat and on firing up the Dynon for configuring and testing, it showed OK - battery full.
 
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