SV320 Back up battery

Jeff1

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Aug 29, 2020
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New owner from an estate, so there’s no one to ask the obvious. I have a Skyview Classic 10” and 7”. I get a “back up battery inop” annunciator on start up on the 7”. I did a battery test on the 10” and it passes. Looked into the avionics bay and see one SV320.
Question, is it possible to run both units off one SV320? would it be typical to install one back up battery on one SkyView and not the other?
 

thibault

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Oct 25, 2009
Messages
191
If you want the power to both screens backed up, you have to have two batteries. Hard to say what others do, but both mine are backed up.
 

maartenversteeg

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Oct 26, 2011
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One backup battery goes with one Dynon display, there is no coupling of one backup battery to two displays, the display takes care of regulating the charge current to a backup battery.
But is seems a perfectly reasonable choice to provide one display with a backup battery, you want to backup the system in case the main airplane power is lost. At that point only having a single (maybe the main) display working seems a reasonable system setup. It's a failure case that you are trying to survive and having one Dynon display working should give you a good chance to make it to an nearby airfield.
 

preid

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Jan 22, 2010
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One backup battery goes with one Dynon display, there is no coupling of one backup battery to two displays, the display takes care of regulating the charge current to a backup battery.
But is seems a perfectly reasonable choice to provide one display with a backup battery, you want to backup the system in case the main airplane power is lost. At that point only having a single (maybe the main) display working seems a reasonable system setup. It's a failure case that you are trying to survive and having one Dynon display working should give you a good chance to make it to an nearby airfield.
It’s more than a failure case, in my case I need it for engine startup as the battery can sometimes go below the minimum required to continue powering the display. One Example is colder weather putting more stress on battery as prop works through the molasses of oil.
one battery is certainly enough. And very much encouraged. I flew my aircraft back 30 minutes solely on backup battery powering the display when my solid state system wouldn’t power up. I had no need for 2 displays, but if you needed to fly more than an hour having the displays on one at a time would allow for each to extend the life of one battery at a time. for you legalistic folks, I mean over water or the desert where there isn’t an airport closer than 1 hour.
 

swatson999

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Oct 6, 2010
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Backup batteries are pretty cheap...why wouldn't you install them for each display (I have an SV-1000T and a D6, both backed up with their own batteries)?
 

airguy

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Backup batteries are pretty cheap...why wouldn't you install them for each display (I have an SV-1000T and a D6, both backed up with their own batteries)?
If you were asking me, it was simple - If I ever get to the point where the Dynon screens are operating on backup power in flight, I don't need the other screen.

My airplane is set up for IFR ops - if I'm IFR and electrically normal, then I have my IFR navigator (which does NOT have it's own backup) online and running. If my alternator dies, I switch on my backup alternator and continue. If the SECOND alternator dies, I now have about 45 minutes of aircraft battery reserve running my essential bus and IFR capability to get on a runway, or at least under the cloud deck. After that point all my electrons run out and I lose engine power, since I'm electrically dependent for both fuel and spark. At that point I'm a glider, and a VFR one - but a single backup battery on the primary screen in front of me provides me with GPS mapping and wind direction as well as synthetic vision for the glide down to a, hopefully good, landing within glide range. There's no scenario I can build in my head that requires a backup battery for the second screen that has not already been accounted for another way. By the time the backup battery is in use, I'm already three failures deep on a single flight and planning for that, or further down the chain from that, is simply futile in the Part 91 world.

As was mentioned earlier, I do power up my primary screen on its battery on every start, and let it boot while getting seatbelts on and cockpit arranged for start, so I have engine instruments available without a brown-out on the battery voltage. It also allows me to verify the function of the backup battery on every start.
 
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swatson999

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I was asking kind of in general...you have a lot of fail-operational mechanisms (backup alternator) which you need because of an electrically dependent engine.

I was thinking in more general terms that a backup battery is cheap, and available for other kinds of failures than just alternator failures (failed power lead, albeit the Dynon does have two; whatever you might think of).

I'm the kind of guy who hates to have a capability there and not implemented, especially when the cost is so low, and it would bug the ever-loving snot out of me to have one screen stay on and the other reboot at every start if I can keep them both up and nicely running for just a couple hundred bucks. I have a 430W that mildly annoys me that they didn't build in backup battery capability for it, but since it's not available, I don't mind it near as much as I would something that has the ability but which I cheaped out on.

But I get your particular situation.
 

Raymo

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I was asking kind of in general...you have a lot of fail-operational mechanisms (backup alternator) which you need because of an electrically dependent engine.

I was thinking in more general terms that a backup battery is cheap, and available for other kinds of failures than just alternator failures (failed power lead, albeit the Dynon does have two; whatever you might think of).

I'm the kind of guy who hates to have a capability there and not implemented, especially when the cost is so low, and it would bug the ever-loving snot out of me to have one screen stay on and the other reboot at every start if I can keep them both up and nicely running for just a couple hundred bucks. I have a 430W that mildly annoys me that they didn't build in backup battery capability for it, but since it's not available, I don't mind it near as much as I would something that has the ability but which I cheaped out on.

But I get your particular situation.
You might want to consider the TCW backup battery. It would not be charged by the Dynon EFIS connection (or could it?) but could power most of your critical devices in a single box.
 
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