pkofman

mooney m20m dead batteries

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So im in canada , its colder today... not really cold as inn Canada could,  just 5c. I have not flown the plane in a week and it is in an unheated hangar but  the Tanis is plugged in. 

Today when going to start the plane the #1 was dead.. not enough to turn the prop over. Usually when that happens I go to #2 and the plane will start

But today everything was basically dead. I checked to make sure I had not left anything running . everything was off . I did not leave anything on when I last left the plane

The only thing that runs in the plane is the little clock when the master is off

Both  batteries are only about a year old

I did not have any issues in the warmer weather.

Any ideas on what might be draining BOTH batteries ( I really would have thought that the batteries could survive a week at 5-10c) and does anyone make something I can plug into the shore power plug to keep the batteries charged ( trickle charger) when the plane is sitting In the cold Hangar. 

BTW, I always run the plane about 2 time per week but I was away last week so it was about 10 days without a start

Thoughts. 

Peter

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Sorry to hear about your Battery challenges, Peter...

The best thing to use to keep things charged is a battery minder with some parts to connect both batteries at the same time... it can be wired to a single socket inside the plane on the back wall, or outside the plane where the GPU socket is... the BM is a modern charger/conditioner designed to best match battery manufacturer and battery type...

It is near impossible to drain both batteries at the same time... as only one battery is connected at a time...

What batteries do you have Gill or Concorde?

Hmmm even Gill batteries usually last two years...

PP thoughts only, not a mechanic...

Best regards,

-a-

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The clock draws 4ma. That would drain the battery flat in about 4 months. So a week is not a problem. Battery minders are great but a good battery should last well more than a week. I am guessing you need two new batteries. Hold old are they?

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Thanks for the feedback 

The batteries are only 2 years old!!!!!!

I believe they are gill

this is not the first time . I have had off and on issues wherein batt 1 dies and I have to start on 2 .

Once its running for a bit  it recharges and I can start on 1 again

I did not have this issue through the summer 

and to be honest I double check everything .....everytime I leave the plane just to be sure I did not leave something on.....

Hard to fly a plane that wont start....

BTW can I "jump start" this plane if someone plug a changing gizmo into the GPU socket at the side.. would that work

Peter

 

 

 

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I had that problem a couple weeks ago in my 252. I flew out to Utah and next morning turned the master on. Everything was dead. It turned out that the baggage compartment light had been turned on inadvertently. I’m thinking of taking the bulb out to prevent this from happening again.


Sent from my iPhone using Tapatalk

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Peter,

   I don’t know if the M is the same as the 1997 Ovation but I had a similar problem. I accidentally hit the baggage light switch while removing cargo from the baggage area. It was daytime and I didn’t see the light come on. It killed both batteries. The newer Ovations have a timer on the light switch that turns it off after a few minutes. Mine does not. The avionics shop checked the system and found the switch had drained BOTH batteries. I thought only one battery would be drained but it turns out it WILL drain both batteries. I removed the bulb so it would never happen again. I had to replace both Concordes because they could not be saved. Needless to say, that was an expensive lesson.

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38 minutes ago, pkofman said:

Thanks for the feedback 

The batteries are only 2 years old!!!!!!

I believe they are gill

this is not the first time . I have had off and on issues wherein batt 1 dies and I have to start on 2 .

Once its running for a bit  it recharges and I can start on 1 again

I did not have this issue through the summer 

and to be honest I double check everything .....everytime I leave the plane just to be sure I did not leave something on.....

Hard to fly a plane that wont start....

BTW can I "jump start" this plane if someone plug a changing gizmo into the GPU socket at the side.. would that work

Peter

 

 

 

Gills last two years. I have had much better success with Concorde.

You mention that if one battery is dead then you just switch to the other one and it starts. So your batteries have been getting weaker recently and the recent cold weather made it worse. I would not take off on a jump start with a dead battery, your airplane is speaking to you, you either have a bad battery (or both) or something is wrong in the charging system.

Jump starting won't fix the battery. It may get you in the air with a bad charging system and two dead batteries - not good. As you replace both batteries, do a Mooneyspace search for "Battery Minder".

 

 

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Well ill check again that I did not leave something on...it would not be the first time I did something bad but I honestly thing I did not

I  researched the battery minder thing.... from what I can read in the forum it seem that some dont love them and they dont always play nice with the batteries but I am a complete newbie on that subject.......maybe they have improved or they need to be used a particular way

I just dont know...but I do know that I need to solve thing before we head into  minus Celsius temps.....!

Peter

 

 

 

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38 minutes ago, pkofman said:

Thanks for the feedback 

The batteries are only 2 years old!!!!!!

I believe they are gill

this is not the first time . I have had off and on issues wherein batt 1 dies and I have to start on 2 .

Once its running for a bit  it recharges and I can start on 1 again

I did not have this issue through the summer 

and to be honest I double check everything .....everytime I leave the plane just to be sure I did not leave something on.....

Hard to fly a plane that wont start....

BTW can I "jump start" this plane if someone plug a changing gizmo into the GPU socket at the side.. would that work

Peter

 

 

 

 

Your battery is likely sulfated. I won’t speculate as to why. It you should either be replaced or serviced with a desulfating battery minder. I know that Gill gets a bad rap around here but I have had them last >5 years. My current Concorde is ~7 years old and very strong. Charging a dead battery with the ship’s alternator is hard on both the battery and the alternator and could shorten the life of either or both.

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Here is a follow. up question.. do those of you with an. M20m or model with a similar battery set. up ..... Do you always run on #1 and assume that will trickle. charge the. #2   Do you alternate batteries each flight  . I. typically alternate batteries.. Switch them for every flight.  What is the recommended protocol and others procedure on the batteries. BTW I fly this plane about 100-125 hours a year or 2+/- hours a week. It should be enough to keep it healthy

Peter

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11 minutes ago, pkofman said:

Well ill check again that I did not leave something on...it would not be the first time I did something bad but I honestly thing I did not

I  researched the battery minder thing.... from what I can read in the forum it seem that some dont love them and they dont always play nice with the batteries but I am a complete newbie on that subject.......maybe they have improved or they need to be used a particular way

I just dont know...but I do know that I need to solve thing before we head into  minus Celsius temps.....!

Peter

 

 

 

Any modern battery minder/tender with 24v capability should work fine. I don’t recall seeing any “anti battery conditioning” posts. That would be a challenging position to defend with anything that resembled facts.

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If you buy a batteryMinder, you need to specify if your using a Gill or Concorde. I had mine converted to a Concorde unit after I replaced the Gills. Check the website and you will see there is a difference.

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@Don has a drawing of a timer circuit for the baggage light

Edited by Yetti

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Check the draw on the battery to make sure you don't have a short to the hot bus. I once had a Cessna 402 that would drain a battery. I solved the problem by pulling all the C/B's and disconnect all fuses.. I placed an  ammeter in series on the positive pole. It should read zero. I then energized the C/B's one at a time until I found the culprit. It turned out to be a reading light in the cabin that had a switch that would not fully disconnect the circuit. It was such a weak connection that the bulb would not illuminate, but enough to draw down the battery.

 

 

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3 hours ago, LANCECASPER said:

Gills last two years. I have had much better success with Concorde.

 

Same here.  Gill for me was garbage for me.  Probably bad batch.  Have 3 years on current Concorde--no issues, and its sealed so no worries about spillage.  I did have to buy the Concorde specific charger though.  

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Gills only lasted 2 years max...switch to the Concordes with the right BatteryMinder and you'll get five years.

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2 hours ago, pkofman said:

Here is a follow. up question.. do those of you with an. M20m or model with a similar battery set. up ..... Do you always run on #1 and assume that will trickle. charge the. #2   Do you alternate batteries each flight

I always alternate batteries every flight.  (Major engine start)   We had a discussion at the MAPA PPP this September, the circuit to charge the second battery is not smart, it is only a single diode to each battery  from the hot side of the master relay protected by a 5A fuse.   If for whatever reason the "trickle charging" battery goes below a voltage where 27.3V will let it draw more than 5A, then the fuse blows and you are no longer charging that battery. 

If you alternate batteries, then you are guaranteed to charge each one when it is the selected master.   You can only detect this failed fuse by either examining the fuses directly (there are 3-4 in the aft avionics area) or by checking the voltage on each battery while charging.  The selected battery should be at 28.. and the second at 27... if the second is down at 24, then it isn't getting its trickle.    You can also tell by switching to the second battery and if it starts pulling lots of Amps, then it wasn't "topped off".

As for the OP's problem, I would want to know the serial# first as the lights and equipment that can drain the battery without the master enabled change from year to year.   But if you zeroed the batteries they are probably shot, I have gotten years of good service from Concorde batteries, and have never had to use a battery minder.   You can try and nurse them back to 24Vs... and then look for DC load when the master is off.. it could be a bad diode.. 

If it is a light then they are supposed to be powered off of battery #1 only.. but the 5A fuse is why Mooney says that if a battery is "Dead" it shouldn't be just started on the second battery, it should be charged up first.   A start with a dead battery on standby will guarantee the circuit blows the fuse as soon as you engage the alternator.  

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2 hours ago, Yetti said:

@Don has a drawing of a timer circuit for the baggage light

Thanks Yetti. I gladly share my timer circuit design, or I will build one for anyone for little more than the cost of parts.

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@pkofman, when was the last time you did a capacity test?  If these values fall below what Gill recommends, you need them replacing...2 years old or not.  Scrap them and get a pair of Concordes...model# RG24-15M.

Steve

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Summary on Long body charging systems and battery conditioning...


1) kept alive circuits have been known to at least kill battery#1...  cabin lights and cigarette lighters with things left plugged in like portable ADSB devices.   Great to have on the check list...

2) accidental baggage light on...happens easily, and frequently-ish...

3) daylight activation is hard to detect... but, easy to find when looking...

4) Alternating batteries every flight makes technical sense, whether it is on the check list or not...

5) Jump starting the plane using the GPU has so many things wrong with it.... tough on everything from the charging system to the batteries and everything in between... it is one thing to jump a weak battery, but a drained battery is different...

6) Battery minders work.

7) Battery minders are expensive.

8) Battery minders are designed to be battery specific for a reason.

9) The ship’s charging system works adequately for what it is supposed to do.  It isn’t as battery friendly as a Battery minder is...

10) when charging and conditioning at the hangar, use the best device you can... this extends the life of the battery.

11) Battery Minders are not needed... they are wanted.

12) For the O... the POH clearly states the Concorde battery is the usual battery choice.  The Gill is listed as an alternative.

13) Plugging in a properly wired battery minder is a simple single external plug. It conditions both batteries at the same time...

14) my Gill experience in the O... they were unchargeable after two years... starting from the day I got the plane... getting a new Gill every year at annual... I even used the Gill specific battery charger made by Gill...

15) biting the bullet to swap over two Gills to two concordes and getting a battery minder... that takes a commitment...

16) Switching one battery at a time should be possible... when making that decision, consider how the charging system works charging one battery and trickle charging the other...

17)  For additional info, review the wiring diagram for how the system is wired... specifically where the diodes are in the system... they seem to have some sensitivity...

18) Best charging and desulfating/conditioning is done by a battery minder specific to the battery. This is a maintenance step... a good standard for comparison purposes...

19) The ship’s charging system is not as skilled at charging and Conditioning, but works very well at maintaining the battery charge as high as practical...

PP thoughts only, not a mechanic... I have a pair of Concordes in the tail... all stuff I learned on MS... nothing original.

Best regards,

-a-

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Wow.... now that is a  fantastic reply and a great summary....BTW I really know  absolutely nothing about battery minders

What I do know is that if I was to get stuck somewhere with dead batteries I would have no choice but to figure out some way to get a charge or boost or something so that I could get running and home

the shop is having a look. around today and ill report back ..... 

 

Peter

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With two batteries and a working alternator system...

getting stuck should be highly unlikely...

or your procedure needs work...

or mag health could be an issue... combined with champion spark plugs...

or the charging system needs work...

cold in NJ is +20°F living outside... no electricity nearby...

you get one good chance to start an O360...

make it a good one.

:)

 

let’s build some confidence...

MS style... :)

 

Go MS!

best regards,

-a-

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20 hours ago, BillC said:

Peter,

   I don’t know if the M is the same as the 1997 Ovation but I had a similar problem. I accidentally hit the baggage light switch while removing cargo from the baggage area. It was daytime and I didn’t see the light come on. It killed both batteries. The newer Ovations have a timer on the light switch that turns it off after a few minutes. Mine does not. The avionics shop checked the system and found the switch had drained BOTH batteries. I thought only one battery would be drained but it turns out it WILL drain both batteries. I removed the bulb so it would never happen again. I had to replace both Concordes because they could not be saved. Needless to say, that was an expensive lesson.

Concur. I did the same thing in my J with the overhead light by the cabin door. Hit it with my head reaching for something in the back. Came back to a dead battery. Light is so anemic you can't see it in the daytime.

Brian

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@pkofman if your plane has TKS the fill port door makes a great place to put the battery minder connections. We just rotate a single charger every time we fly. I would recommend a capacity check while the shop has the plane open (have them pull both batteries) and would not let the plane leave the hangar without at least one new concord. 

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