[rvmills]

I just posted a similar thread to this on the Dynon site, but thought I'd put out a query to Team VAF to see if anyone has any thoughts on an issue that just popped up with my EFIS D-100 (especially those with Dynons, but any thoughts from the electrical wizards in the group are most welcome!)

My EFIS D-100 is shutting off early during the 30 second shutdown cycle when I turn the battery switch off, and it has me scratching my head. This appears to have started since updating to v 5.0, and installing the AP-74 and Servos, but I do not know if it is related. Here's the set-up:

- D-100 (w/ BU Batt), powered via a dedicated CB on the avionics buss.
- D-10A (w/BU Batt), powered via a second dedicated CB on the avionics buss.
- AP-74 and 2 SV-32 Servos, powered via a third dedicated CB on the avionics buss.
- D-100 Keep Alive, powered via a fourth dedicated CB to hot Batt.

I recently sent the D-100 back to Dynon after my v 5.0 update failed, and it came back (very quickly I might add!) with 5.0, and all indications are normal in flight. AP is functioning, and everything on DSAB is good to go.

As I shut down the aircraft, when I turn the avionics master off, the D-100 and D-10A both begin their 30 second shutdown timer as they did before. However, if I turn the Battery master off during the 30 second countdown, the D-100 shuts off immediately. The D-10A continues it's countdown to zero, then shuts down, as it did before the 5.0 update and the AP install. That's the way the D-100 used to behave as well...this is a new phenomenon, and the batt sw never had this effect before. Both EFIS's always came on with the Av Master, and began the 30 sec timer when the Av Master was shut off.

Suspecting the D-100 backup battery could be part of this (it was drawn down to zero during my earlier 5.0 update issues), I tried to bring the D-100 up on backup batt with Batt and Av masters off, and it booted up just fine. I did note that the clock was wrong...first time I've noted that. I've flown the airplane a few hours since the AP install, so I think the BU batt should be fully charged now.

My questions to Dynon (slightly reworded here) were:

1. Given that the power wiring hasn't changed for the D-100 (the only change I made to the D-100 wiring during the AP install was to tie the AP-74 and servos into the D-100 DSAB A/B wires...power wire was not touched), is there anything anyone can think of that would cause this behavior?

2. Could it be an issue with the charge state of the BU batt (and is there any way to check that state...maybe via a menu, vs. pulling it out and checking it with a meter)?

3. Given that the clock was wrong, could there be something up with Keep Alive that could cause this? Keep Alive is the only piece that goes to the battery, but it is unswitched (CB protected, but not going through the batt switch) and I haven't changed the keep alive circuit wiring, so that steers me away from this as the culprit...but then there is that clock thing!

4. While I troubleshoot this, and until I figure it out, any thoughts on whether I am causing harm to the D-100 if I shut off the Batt master and the EFIS shuts down as described (I can wait the full 30 secs for the EFIS to shut off before turning the batt off, but I'd like to make sure I don't have another issue going on).

Any ideas you guys might have are very much appreciated! Thanks much!!

Cheers,
Bob

 

[rvmills]

Follow-up

I've been working this with the great folks at Dynon, and just wanted to post a follow-on here.

This shutdown anomaly only happens when I have the Keep Alive connected and I turn the battery switch off before the D100 30 second shutdown timer gets to zero. If I pull the KA CB, and turn off the battery while the 30 second timer is going, the timer continues to zero, and the shutdown is normal, with no loss of the clock time.

I've traced the KA circuit, and it appears to be wired OK, with pin 2 on the Dynon DB25 (KA) seeing battery voltage with the batt sw on or off (as it should). So this premature shutdown is quite odd.

Dynon is seeing issues with KA, and have been recommending removing KA, or not installing one. Not sure what the issues are, or if my shutdown anomaly is one of the ones being seen by others. Dynon also said they are seeing a number of cases where the BU batteries are being drained quickly in units that do not have a KA, so it's kind of a rock and a hard place story, and they are working very hard on it!

If I leave the KA CB out when the airplane is in the hangar, the D100 (Bus Master) Backup Battery voltage drops 2-3 volts in 2-3 days. My D-10A slave unit (with no KA) has not seen the drain issue. As mentioned, it appears that others are having this drain problem too, after updating to Firmware 5.0. "Guccidude1" Dan has seen this happen in his RV-9A Bus Master D180, and when he moved his D100 BU battery over to the D180, the second battery was drained quickly as well (with KA disconnected).

Dynon has been great at listening to all of our input, on the phone and in the forum. I'm sure we'll hear more soon!

Cheers,
Bob

 

[FrankK90989]

Same here , but with no BU battery. D-120 Was disconected per Dynon, D-100 was the only thing left to blame. After the 5.0 update I found my battery very low. Removed KA. battery drain fixed! The time is furnished to the Dynon from my GPS on start up and this works better anyway.

 

[rglick]

Battery Drain

It's also draining the internal battery to the tune of a couple volts per day. The D1XX needs about 14.2v on the Internal battery to run the unit after losing A/C power. Lower than that you will notice the unit shutting down either with or without the 30 second shutdown warning. Dynon has assured us that they are diligently working on this issue and should have something shortly.

 

[rvmills]

Same here , but with no BU battery. D-120 Was disconected per Dynon, D-100 was the only thing left to blame. After the 5.0 update I found my battery very low. Removed KA. battery drain fixed! The time is furnished to the Dynon from my GPS on start up and this works better anyway.

Frank,

I'm still scratchin' my head on this one. Seems some see the drain with KA attached, and others are having the drain with no KA attached (like me). With my KA CB pulled last week, the BU Batt drained. This week, with the KA CB in, the BU Batt re-charged. My other issue with my KA is that it is causing this shutdown anomaly, with a charged BU batt (see continued post below).

It's also draining the internal battery to the tune of a couple volts per day. The D1XX needs about 14.2v on the Internal battery to run the unit after losing A/C power. Lower than that you will notice the unit shutting down either with or without the 30 second shutdown warning. Dynon has assured us that they are diligently working on this issue and should have something shortly.

RG,

Concur with you on BU batt voltages. When my BU batt got down to 13.4V, during the 30 sec shutdown timer, I could watch the BU batt volts drop from 13.4 to 12.0 in about 5 seconds, and the unit went dark...just like you said.

The odd thing I'm seeing is that even when I have a full BU batt (16.5V), if I turn off my batt switch during the 30 second timer, the D100 goes dark immediately, while the D10A continues it's 30 second clock. This only happens if I have KA on...with KA off, the D100 also continues its 30 sec clock, just like it did before 5.0.

I'm OK with permanently pulling KA from the D100, but if we're seeing BU battery drains with no KA, I'm just not quite ready to do that, as KA did recharge the BU batt this week (will go out today and see what I find!). I also want to be able to help Dynon test any SW patches if they need the assist, so I'll leave the KA in and control it with the CB.

At any rate, I know they are furiously working this!!

Cheers,
Bob