Aspen 1000 PFD - Battery Countdown Warning

[mooneyman]

On climb out yesterday I got a battery warning countdown indication. The display dimmed and the warning box appeared displaying "Battery level in 15s".  

 

The countdown timer would start and then disappear. After a few seconds, the warning box would reappear and start counting down again. Then it actually indicated "on Batt 60% remaining" then disappeared again.  Next time it indicated " on Batt 70% remaining" then disappeared. I did not notice any low voltage indication or discharge on the ammeter. 

 

After about 3 or 4 minutes( seemed like a lot longer)  the warnings stopped. I had considered returning to the airport, but when the warnings stopped I decided to continue. The remainder of the short 30 minute flight was uneventful as was the return flight later in the evening.

 

Anyone have similar experience? Electrical gremlins? Could the recent extreme cold temperatures have anything to do with this?  Aircraft is stored in unheated hangar. 

 

Thanks-- Patrick 

[rob]

Sounds like a gremlin. That message comes on when the Aspen loses power from the bus. Check it's breaker, maybe, as a starting point.

[Cruiser]

yes, most likely culprit is the circuit breaker/switch. They can get very hot and develop enough resistance to lower the input voltage to the point the Aspen wants to switch to internal power.

[mooneyman]

Sounds like a gremlin. That message comes on when the Aspen loses power from the bus. Check it's breaker, maybe, as a starting point.

  

yes, most likely culprit is the circuit breaker/switch. They can get very hot and develop enough resistance to lower the input voltage to the point the Aspen wants to switch to internal power.

Thanks guys!!! I check it out and report back!

[peter]

The countdown is displayed when the unit first switches onto battery while it is figuring out how much battery charge is remaining. It has to let the battery discharge a little to figure out how much charge is left.  The real question is why is the Aspen switching to battery - this requires the input voltage to remain below 12.3V for a short period of time. Check your charging system.

[Marauder]

Did you ever get a resolution to this? Just curious...

[Oscar Avalle]

I had a similar problem, my Aspen announced out of the blue on an approach one day that it was switching over to battery power. That called my attention right away. After I landed it switched back to the main power. After looking at different options we decided that the regulator was not working well and the voltage was too low. Once I changed the regulator and adjusted the voltage it did not happen again. However, I had to also change the battery in my Aspen because it stopped charging at all... (most likely unrelated).

[Marauder]

Oscar -- is the battery a Ni-Cd or Lithium? Do you remember what it cost you?

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[Oscar Avalle]

Marauder - I don't remember the kind of battery. But it was exchanged under warrranty. I talked with ASPEN and they were VERY HELPFUL, in particular considering that I was not in the country.

[mooneyman]

Did you ever get a resolution to this? Just curious...

We think it's the internal battery. Replacement cost approx. $175. New battery is on order and should be in this week. I'll post another update after we get the new battery installed.

[mooneyman]

Internal battery was replaced on Friday. My avionics guy was sure he had solved the problem. Aspen was working fine during ground check. On climb out today, voltage into Aspen dropped down to 6v. Voltage across rest of bus maintained 13.2v. Aspen switched to battery backup. During 20 minute flight voltage into Aspen varied from 3-12v. It never returned to above 12.8v and stayed on battery.

Problem is that voltage into Aspen only drops when in the air. He was not able to reproduce the voltage problem on the ground. I'll have him check the regulator as Oscar suggested. More to follow......

[Marauder]

Internal battery was replaced on Friday. My avionics guy was sure he had solved the problem. Aspen was working fine during ground check. On climb out today, voltage into Aspen dropped down to 6v. Voltage across rest of bus maintained 13.2v. Aspen switched to battery backup. During 20 minute flight voltage into Aspen varied from 3-12v. It never returned to above 12.8v and stayed on battery.

Problem is that voltage into Aspen only drops when in the air. He was not able to reproduce the voltage problem on the ground. I'll have him check the regulator as Oscar suggested. More to follow......

Thanks for the update. Hopefully not a major issue. Your Aspen should be on a separate switch. You may want to make sure connections are secure on it. Could be the variation is caused by either poor connections on the switch or the switch itself. Vibration in flight is a bit different than ground runs.

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[MooneyCFII]

Internal battery was replaced on Friday. My avionics guy was sure he had solved the problem. Aspen was working fine during ground check. On climb out today, voltage into Aspen dropped down to 6v. Voltage across rest of bus maintained 13.2v. Aspen switched to battery backup. During 20 minute flight voltage into Aspen varied from 3-12v. It never returned to above 12.8v and stayed on battery.

Problem is that voltage into Aspen only drops when in the air. He was not able to reproduce the voltage problem on the ground. I'll have him check the regulator as Oscar suggested. More to follow......

Since the voltage on the rest of the bus remains at 13.2V it is not the alternator or the alternator controller (voltage regulator). If the alternator was not producing output the bus voltage would be at 12.7V or lower.

 

(Just as an aside, 13.2V for your main bus voltage is a bit low. I would expect normal bus voltage in flight to be 13.8V - 14.4V depending on temperature. Have you confirmed the bus voltage using a calibrated meter?)

 

Since the problem only afflicts the Aspen and nothing else on the bus, you are trouble-shooting ONLY the circuit to the Aspen. That means the breaker, the power wiring from breaker to the Aspen, the power connector to the Aspen, and the Aspen itself. Since the voltage is varying going to the Aspen then you are most likely looking for an intermittent loose connection. Since the breaker isn't tripping you are not looking for a short-circuit, e.g. wiring chafing against something else. 

 

Since it only happens in flight, what is changing under the panel between sitting there on the ground and in-flight? I have seen improperly-secured wiring snag on elevator and aileron pushrods/cables before. Carefully inspect the wiring from breaker panel to the Aspen to see if it is impinging on the flight controls at all. 

 

I am a bit surprised that Aspen had you replace the back-up battery since it is clear that it is working properly, i.e. carrying the load for the Aspen after the bus power goes away, something that is clearly indicated by the Aspen indicating bus voltage less than 12V while the voltage on the bus itself remains at 13.2V. 

 

Good luck. I think you will find that careful inspection of the wiring and connectors will locate the problem.

[Cruiser]

please re-read post #3 above and do yourself a favor and replace the power switch.

[MooneyCFII]

Where's MooneyMite when you need someone to stir-up the discussion about "how more reliable glass is than round dials and how you never need to fix it?"

Well, in this case it doesn't appear that the glass actually failed. OTOH, my iron AI rolled over and died the other day.

 

Had the bearings in an AI fail catastrophically in a gyro once. When you turn the gyro wheel loose in the enclosure while spinning at full speed it makes one HELL of a bang followed by the most ungodly thump-thump, rattle-rattle. My first though was that the engine had thrown a rod. 

 

No, I am just SO tired of failed iron gyros and failed vacuum pumps. When the Mooney's panel gets a face-lift all the air-driven iron gyros and the vacuum pump are going to that great gyro overhauler in the sky. The vacuum pump pad on the engine is going to get a small alternator to provide backup power to EVERYTHING. With modern avionics and LED lighting a 20A backup alternator will be able to carry most if not all the load. 

[MooneyCFII]

please re-read post #3 above and do yourself a favor and replace the power switch.

And you may be right. But just randomly replacing things without determining they have failed is not the best troubleshooting technique. If you think that the switch is the culprit, put a voltmeter across it. Any voltage more than about 0.1V means the switch/breaker is bad and that is easy enough to test.

[Oscar Avalle]

Internal battery was replaced on Friday. My avionics guy was sure he had solved the problem. Aspen was working fine during ground check. On climb out today, voltage into Aspen dropped down to 6v. Voltage across rest of bus maintained 13.2v. Aspen switched to battery backup. During 20 minute flight voltage into Aspen varied from 3-12v. It never returned to above 12.8v and stayed on battery.

Problem is that voltage into Aspen only drops when in the air. He was not able to reproduce the voltage problem on the ground. I'll have him check the regulator as Oscar suggested. More to follow......

 

Wow, sorry that you were not able to solve the issue. Let us know what you find out. 

[Cruiser]

Where's MooneyMite when you need someone to stir-up the discussion about "how more reliable glass is than round dials and how you never need to fix it?"

quite right. Many seem quick to point at the glass and blame the "new fangled gizmo" when something fails. Unfortunately you rarely hear them come back and say "oops that wasn't the problem" . 

[larryb]

My new sl30 stopped working in the first month. It was the new circuit breaker, not the radio.

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[mooneyman]

please re-read post #3 above and do yourself a favor and replace the power switch.

Yep, Cruiser was right! It was the PFD switch! Working fine now! Thanks!

[Cruiser]

Your welcome! 

Glad I could help  

[MooneyCFII]

Did you test the switch first (as I suggested) or did you just replace it?

[mooneyman]

Did you test the switch first (as I suggested) or did you just replace it?

We tested it first.

Internal battery was not holding charge very well and needed to be replaced anyway.

Thanks to everyone for the help!

[MooneyCFII]

Where's Mooneymite when you need someone to stir up the discussion how "glass is only as reliable as the switches, circuit breakers and batteries that feed it?"

:-)

How true. And iron gyros are only as reliable as the #$%^ vacuum pump that feeds them. Given the choice, I'll bet my butt on the switch, the circuit breaker, and the battery before I will bet my butt on the vacuum pump. Give me an all-electric panel with two alternators over a half-electric/half-vacuum panel any day of the week.