291 kts...but battery 2 is toast?

[aggiepilot04]

Perfect conditions getting out of Gunnison, CO yesterday and back to Austin.  With a healthy tailwind (was doing close to 300 kts across the ground at one point!), my Mooney time machine allowed skiing until around 2PM and still making it home before sunset.  It would have been a shorter flight than that, but I had to come down early because my O2 usage was greater than expected (that's a topic for another thread).  Too good to be true, right?

Well, it was.  When I went to shut down, I flipped off the alternator/autopilot switches (old habit since I no longer have an avionics master), and my panel went dark.  Flipping the alternator switch back on had no effect, but everything came back to life on when I switched over to battery 1.  I shut down completely, restarted on battery 1, then flipped to battery 2 and everything stayed on (showing a +3 amp charge).  I think this was the same sequence I followed before departing Gunnison, so it's possible that battery 2 was dead from the beginning.  It either did not take a charge on the 2.5 hour flight or it failed hard somewhere along the way.  On a side note, I think I will always depart on the same battery that started the engine from now on...especially if IFR.

I then shut down, put the plane in the hangar, and pulled the battery panels.  No lose connections.  Both batteries had what appeared to be condensation on them.  Is that normal?  It was -31C at FL250...would that have anything to do with it?

The batteries are Concorde and were installed new in November 2013...so a little over 3 years old.  No signs of weakening or trouble starting.  I did, however, have a new Skytec starter installed last week because of a slow oil leak from a starter seal.  Could that have anything to do with it?

I believe this is also unrelated, but manually opening the alternate air door pops my annunciator breaker.  This started happening before the departure to Gunnison, so it is also a recent development.

So I guess my question is...this has to be a bad battery right?  Since the alternator is showing a positive charge and appears to power the panel?  And if so, shouldn't I get more than 3 years out of a Concorde battery?

Thanks in advance.

Edited February 22, 2017 by aggiepilot04

[carusoam]

Uncharged batteries can freeze.  Frozen batteries can break their cells...

the cells of the Concorde gel batteries are thin and may not be durable to mechanical challenges.

might be a good idea to check on the operating temperature requirements for the battery.  Gives a good reason to call Concorde... ask for a discount while buying the next one... 

Sounds unusual for a Concorde battery.

If you can't charge it in the hangar, it probably has a dead cell.

Nice GS!

PP thoughts only, not a mechanic...

Best regards,

-a-

Edited February 22, 2017 by carusoam

[aggiepilot04]

15 minutes ago, carusoam said:

Uncharged batteries can freeze.  Frozen batteries can break their cells...

the cells of the Concorde gel batteries are thin and may not be durable to mechanical challenges.

might be a good idea to check on the operating temperature requirements for the battery.  Gives a good reason to call Concorde... ask for a discount while buying the next one... 

Sounds unusual for a Concorde battery.

If you can't charge it in the hangar, it probably has a dead cell.

Nice GS!

PP thoughts only, not a mechanic...

Best regards,

-a-

Thanks for the quick response.  My first thought was that I had bumped the overhead light switch after arriving at GUC.  The plane was outside the first night, so a potentially dead battery would have been exposed to freezing temps.  But I know I was on battery 1 at that point (and as best I can tell, the overhead lights are always powered by battery 1).  I also know for sure that I started on battery 2 before departing AUS, so battery 2 wasn't dead at that point.

Point being, I *think* both batteries were somewhat close to fully charged before being exposed to freezing temps.  I don't see any limitations on the operating temps, but Concorde provides ratings at -30C (http://www.concordebattery.com/flyerprint.php?id=41)...so I don't think I exposed the batteries to anything excessive?  Maybe it was on the brink of failure, and the temps in the flight levels pushed it over the edge...

Either way, I will definitely call Concorde and see if they'll work with me.  Thanks again!

[ArtVandelay]

You don't mention anything about voltages on each battery? Can you check via engine monitor or put a digital multimeter on them? Could be just the connection from bat 2 to avionics buss is bad, check circuit breakers, relays in the path.

I would not call Concord until you are sure the battery is bad (pull it and charge it and see it holds charge disconnected from the plane).

[Yooper Rocketman]

On my last flight to Florida with my Rocket (back in December) I saw temps at FL230 below -31.  My Concordes are at least 7-8 years old and mounted in the back of the tail cone (clearly not seeing any heat from engine or cabin).  With the batteries cold soaked from FL temps, it would be normal to see condensation on them when back to more moderate temps on the ground.  Charge and check that battery with it isolated from everything in the system before getting Concorde involved.  Clearly that is too short of a useful life (IMHO).

Nice ground speed!  My last flight saw 295 knots and Chicago Center asking me if I was a turboprop!  I'm not quite as excited to talk about how that 4 hour non-stop from the U.P. to Daytona Beach turned into nearly 7 hours coming home a week later.

Tom

[mike_elliott]

8 hours ago, aggiepilot04 said:

On a side note, I think I will always depart on the same battery that started the engine from now on...especially if IFR.

Here is a clue to what might be your issue. Don Maxwell is getting wealthy selling new battery relays because of switching batteries with engine on. I used to switch batteries when I would switch tanks, but no more. Check this out also.

[aggiepilot04]

55 minutes ago, mike_elliott said:

Here is a clue to what might be your issue. Don Maxwell is getting wealthy selling new battery relays because of switching batteries with engine on. I used to switch batteries when I would switch tanks, but no more. Check this out also.

This would make a lot of sense...for several reasons:

1. I don't have switching batteries on a checklist (yet), so it always winds up being an afterthought.
2. The nature of the failure (with no previous issues with the battery)
3. The fact that the charge rate/voltage still show normal.

Someone in a PM mentioned that I should switch battery 1 and battery 2 to confirm that it was a battery and not a relay.  I'll get back out there tonight with a volt meter to do some more troubleshooting.  Thanks for the insight!

[aggiepilot04]

6 hours ago, teejayevans said:

You don't mention anything about voltages on each battery? Can you check via engine monitor or put a digital multimeter on them? Could be just the connection from bat 2 to avionics buss is bad, check circuit breakers, relays in the path.

I would not call Concord until you are sure the battery is bad (pull it and charge it and see it holds charge disconnected from the plane).

No popped breakers and the voltage according to the panel showed normal (before going dark).  But that would have been showing the voltage from the alternator, right?  Voltage on batt 1 was normal with the alt switch off.  I didn't have my voltmeter with me at the time, but I'll take it out there tonight to further troubleshoot.

[ArtVandelay]

No popped breakers and the voltage according to the panel showed normal (before going dark).  But that would have been showing the voltage from the alternator, right?  Voltage on batt 1 was normal with the alt switch off.  I didn't have my voltmeter with me at the time, but I'll take it out there tonight to further troubleshoot.

Breakers and relays can appear to be closed, but not making good connection, check all with ohmmeter function.

[LANCECASPER]

Before startup it's a good idea to check the voltage on each battery. If one is dead it's a no-go.

[Cruiser]

A three year old Concorde battery should not be failing. You should have a BatteryMinder charger and leave it on both batteries 24/7 when possible. I don't bother when away on a trip but anytime it is in the hangar it is on the charger.

I had my #2 battery go bad, or so I thought but I found the fuse was blown in the charger line and it was not getting a connection. IN the plane I use the #1 battery most of the time (forget to switch) and the #2 get neglected. I pulled the battery and replaced it with new before I realized what had happened. The old one charged right up and is still good (2010) if you need a spare let me know.

[aggiepilot04]

Made it out with the voltmeter tonight. Getting 24v from the switch, 24v on one side of the relay, nothing on the other. It appears that I'm going to need one of these high-priced relays:

http://www.peerlesselectronics.com/store/products/26.57.01.html

I suppose it's not quite as painful as the battery. Thanks all for the help and insight.


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[carusoam]

Thanks for sharing all the details, AggieP.

definitely put the battery test on the pre-flight check list.  The list usually says test both batteries, and then start on the stronger of the two...

The JPI has a voltage gauge that reads to a decimal place.

Once the engine is running, the voltage reading is going to be driven by the alternator...

Battery selector solenoid have a tendency to wear.  If you push it slowly you can get it to turn everything off before it switches to the next battery.

I have two identical batteries.  They get switched every day.  I would prefer to do that prior to engine start than mid flight...

+1 on the BatteryMinder.

TomK, where is your BatteryMinder connection?  I have recently acquired a BatteryMinder and thinking where to run the cord to avoid opening the access panels each time...

Best regards,

-a-

Edited February 23, 2017 by carusoam

[aggiepilot04]

While I'm still at the hangar, here's where mine is. I actually don't have the batteryminder (it's on my list)...just the wiring. And it appears to only be wired to batt 1.


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[aggiepilot04]

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[carusoam]

The battery minder people sell a few additional devices...

There is a specific Y for the two battery system with fuses included, incase something goes wrong.

There are wires with rings that mount to each battery.  The Y mates up directly to these.

i also saw a socket they have that would improve the look of the wire coming through the hole.

I'm starting to consider the plug mounted through the vertical wall in the area that you are showing there.  Open the baggage door and plug in...

Others have mentioned running the cord out around the ground power service area.  Not sure of the details on that without looking closer.

Best regards,

-a-

[LANCECASPER]

The Batteryminder part number for the Y is 210-AY (http://www.ebay.com/itm/BatteryMINDer-SmarTECHnology-Y-Multiple-Battery-Connector-Model-210AY-New-/381932099068?hash=item58eced55fc:g:1uoAAOSwLEtYgyd8) that stays in the avionics bay in the back.

I ran mine out the Oxygen door. Both batteries stay desulfated and charged with one Batteryminder for Concordes (http://www.aircraftspruce.com/catalog/elpages/batteryminder11-14352.php?clickkey=2300274)

[StevenL757]

Aggie...sent you a PM on the relay item.

Regards, Steve

[DAVIDWH]

Not sure all of Don Maxwells wealth is coming from selling battery relays.

Counted 26 Mooneys in his shop for maintenance.

"If you build it they will come"