%$^&**!! Battery Dead Again!

ScottM

ScottM

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iBazinga!
4th time this year my battery went dead from sitting for a couple of weeks.

This past winter it froze and died. I had the maintenance guys check it but it seemed good. Yet it still keeps self discharging ever couple of weeks. I have had it! I told them to put a new one in. I will also be adding a battery minder in anticipation of the winter.

I had to jump the plane twice today to get it started and was only able to run it for a couple of hours I fear the next time I go out the batt will be dead again.
 
GET A BATTERY MINDER although my Concord battery has never let me down and I don't fly nearly as often as you do.
 
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smigaldi said:
4th time this year my battery went dead from sitting for a couple of weeks.
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Scott, something isn't right. I believe you have a Cherokee? I can't think of a reason (other than leaving something on) that your battery life would be so short. What kind of battery, how old? Is there a way you could measure (with everything off) if there is still a current drain or voltage drop from the battery(+) to ground? The Cherokee electrical system is pretty straightforward, methinks there is a short or other source causing the issue.

Gary
 
Something seems very wrong. (hanging head in shame) I didn't fly my airplane
(a cherokee 140) after the annual (March 2009) until 1 August... and it started
right up. I didn't charge the battery or anything. I wouldn't necessarily suspect
the battery.

Good luck
 
Put an in-line load meter on the battery cable to see if you have a drain. Many airplanes have trick circuits that will rob the battery. If you see a Bo sitting in a hangar, there's a good chance the R/H side of the cowl will be open and one of the fuses will be sitting at an odd angle, clearly indicating it is disconnected at one end.
smigaldi said:
4th time this year my battery went dead from sitting for a couple of weeks.

King Airs are notorious for the cabin door step lights, which are on the hot bus and can't be seen in daylight and extinguish automatically when the door is closed.



This past winter it froze and died. I had the maintenance guys check it but it seemed good. Yet it still keeps self discharging ever couple of weeks. I have had it! I told them to put a new one in. I will also be adding a battery minder in anticipation of the winter.

I had to jump the plane twice today to get it started and was only able to run it for a couple of hours I fear the next time I go out the batt will be dead again.
Click to expand...
 
smigaldi said:
4th time this year my battery went dead from sitting for a couple of weeks.
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Harbor Freight sells a little multimeter that normally goes for $5 or so but you can get them on sale for less than $3.

Take the negative lead of the battery loose from the battery with the master switch off and any other load you know about off. Insert the multimeter on the 200 mA range between the battery (-) terminal and the ground wire (alligator clipleads work well). If the ammeter shows anything more than a couple of milliamps (clock, radio memory keep-alive, etc.) then start pulling breakers/fuses until the load current goes down. THen figure out what is on and drawing current.

Here's the calculation. You say it goes dead in a couple of weeks. A couple of weeks is 336 hours. You have a 35 amp-hour battery. A 100 milliampere load will drain that battery dry in two weeks, so this is the order of magnitude current you are looking for.

Jim
 

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Gary said:
SI can't think of a reason (other than leaving something on) that your battery life would be so short.
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You did catch the part in my OP where the battery actually froze last winter. Froze as in solid and needed to be thawed.

I never had this problem until the battery had frozen. My one year old, at that time, battery is now FUBAR. While a voltage test shows good voltage my guess is that there is damage to the plates and the internal resistance of the battery has changed. This is causing a self discharge issue. The only load on the battery when the plane is off is the quartz clock. A typical battery should be able to run for years with that little of a load.

New battery will be installed next week, a 2nd check and any phantom loads will be also performed, the new battery minder is already shipped.
 
Weirdjim explained the test much better than me! But, on reflection, I'm leaning toward an internal short of one of the plates of the battery. Could be from sulfation or a mechanical shift of one of the plates. If the battery did indeed freeze, that scenario is more likely. I "think" that a load test of the battery would indicate whether it's up to par.

Gary
 
Gary said:
Weirdjim explained the test much better than me! But, on reflection, I'm leaning toward an internal short of one of the plates of the battery. Could be from sulfation or a mechanical shift of one of the plates. If the battery did indeed freeze, that scenario is more likely. I "think" that a load test of the battery would indicate whether it's up to par.

Gary
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I had them load test last year at annual but it did not show anything unusual. I am thinking the plates are damaged but not enough to actually be touching an shorting. There may be some residue on the plate that is making a restive connection.
 
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smigaldi said:
I had them load test last year at annual but it did not show anything.
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OK, seems as though we both posted at the same time. But that raises an interesting question. If a battery had a small internal short, would it test OK, but still slowly drain itself down? I suspect so, must be someone on the board with greater knowledge of battery construction.

Gary
 
Gary said:
OK, seems as though we both posted at the same time. But that raises an interesting question. If a battery had a small internal short, would it test OK, but still slowly drain itself down? I suspect so, must be someone on the board with greater knowledge of battery construction.

Gary
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When the electrolyte froze it changed volume. While there was no physical damage to the battery case I think some of the plates got smashed closer together. There could have been then a change in the internal restance of the battery but not a short. With the distance between the plates changed and a possible restive change the capacity of the batter changes. A load tester that is typically found in auto and aircraft shops is a bit clutzy.

Those load testers look at a short period sample of current and extrapolate an answer quickly. To do a real load test you have to have the battery under constant load with what ever voltage it will put out an then plot a voltage vs. time graph.

I used to do exactly that type of evaluation in my early days designing battery operated electronic devices. I have worked with sealed lead acid batteries, NiCAD, NiMH, LiIONs. I have not worked too much with vented lead acid/liquid electrolyte batteries other than when used as back up power sources for large electronic equipment. Those hardly ever had freeze issues as they were in doors. But I have seen what happens to them when a truck hit them! YIKES!
 
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My battery freezes to -20 to -40 between every flight in the winter. Now, granted, I thaw it before trying to start the airplane, but still...
 
I had a brass monkey once.

alaskaflyer said:
My battery freezes to -20 to -40 between every flight in the winter. Now, granted, I thaw it before trying to start the airplane, but still...
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Scott,

If we lived closer I'd give you the extra one that I have sitting in the hangar...been looking for a use for it.
 
The acid mixed with water to make elctrolite, the acid in that mixture will not freeze, the water will making sort of slush ice. this will not normally ruin the battery.

you have a slow draw on the battery that runs it down.

find it and fix it and your troubles will go away.
 
The perfect battery for the 12 volt PA28 Piper models, is the Concorde sealed RG-35AXC "extra cranking" version. It weighs about 3 pounds more than a Gill G-35 or Concorde CB-35A and you do not have to worry about the spillage/corrosion problems of a flooded wet-cell battery anymore. I put one of these in my Cherokee earlier this year and wish now that I would've done it years ago.
 
Replace your battery. Concordx AXC 35RG
Keep it on a battery minder.
Make sure your BUS voltage is no more than 14.1V.

It'll last forever.
 
Finding a small electrical draw, solder 2 wires to a 12/28 volt light bulb, 1 at the terminal end,(+) and the other to the bulb case (-) disconnect the battery cable (either will do) and connect the light bulb between the battery terminal and the cable you removed. If it shows a glow, you have a draw, remove fuses or pop the C/Bs until the light goes out, that is the circuit that has the draw.
 
Neal Howard said:
The perfect battery for the 12 volt PA28 Piper models, is the Concorde sealed RG-35AXC "extra cranking" version. It weighs about 3 pounds more than a Gill G-35 or Concorde CB-35A and you do not have to worry about the spillage/corrosion problems of a flooded wet-cell battery anymore. I put one of these in my Cherokee earlier this year and wish now that I would've done it years ago.
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I got one of these (RG-35AXC "extra cranking" ) for my Warrior earlier this year - Love it.

Scott, when I was first at 10C in the hangar next to the FBO, my battery also froze and died - was very cold with no heat...the replacement only lasted a couple of years and I got a hyrometer to test the specific gravity. It wasn't up to specs and I noticed moisture on top by the vents on a couple of the cells - not good.

Sounds like you have the solution now...new battery AND a battery minder. I have that set up now and think it really helps. The test will be time and cold but from what I've read, it will extend the life of the battery.

Let me kow if you want to use my hydrometer to check the specific gravity.

http://www.engineersedge.com/battery/specific_gravity_battery.htm

Allan
 
Tom-D said:
Finding a small electrical draw, solder 2 wires to a 12/28 volt light bulb, 1 at the terminal end,(+) and the other to the bulb case (-) disconnect the battery cable (either will do) and connect the light bulb between the battery terminal and the cable you removed. If it shows a glow, you have a draw, remove fuses or pop the C/Bs until the light goes out, that is the circuit that has the draw.
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Harbor Freight voltmeter is a lot easier and probably about as expensive.

Jim
 
I've had owners that put in several batteries because they went dead in a matter of days. The shop declares the battery bad without giving it a chance.
You probably have a draw off of the hot buss (not many items) I have found leaking diodes across battery and starter solenoids causing the drain. Using the ammeter in line is my choice for troubleshooting.

Kevin
 
With all the switches off the airplane is pulling 4mA. I imagine that is mostly from the clock in the panel.

A 35Ah battery would take 8750 hours (364.6 days) to discharge under those conditions. My battery was fully discharged in a few days.

Like I said before it is a bad battery probably as a result of when it froze this past winter.

The new battery has been installed and the battery minder is ready to be utilized.
 
smigaldi said:
<SNIP>
Like I said before it is a bad battery probably as a result of when it froze this past winter.

The new battery has been installed and the battery minder is ready to be utilized.
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As was pointed out, the sulfuric acid concentration had to be down to let the battary freeze- the battery was already bad.

According to the link below, it should freeze between 25 (10% acid- weak) and -30° F (51% acid). The battery should be around 33% acid (6 molar).
http://www.colonial-chemical.com/pdfs/battfluid.pdf
 
http://home.att.net/~chicago_climo/CHI2009.gif

This data is form KORD which is closer to Lake Michigan that where I live and does reflect a few degrees of temperature warmer in the winter than what I experience.

The batter was running fine until it froze. Since then it had not been able to hold a charge.

But it is now on it's way to a recycle facility.
 
weirdjim said:
Harbor Freight voltmeter is a lot easier and probably about as expensive.

Jim
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You must be smart enough to read and understand what you are seeing.

you don't have to be very smart to understand the light is on, or off.
 
Tom-D said:
You must be smart enough to read and understand what you are seeing.

you don't have to be very smart to understand the light is on, or off.
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So how bright does it have to be for you to decide that the constant drain is too much? IIRC a 10W position lamp won't hardly glow enough to see it unless you look at it in the dark with a 100 ma current and that's enough drain to kill or at least weaken a battery in a week.
 
gismo said:
So how bright does it have to be for you to decide that the constant drain is too much? IIRC a 10W position lamp won't hardly glow enough to see it unless you look at it in the dark with a 100 ma current and that's enough drain to kill or at least weaken a battery in a week.
Click to expand...

If you don't like the bulb idea, try an LED.
 
Captain Mustard (Scott) repiled: The batter was running fine until it froze.
What do the Yankees have to do with this?

Too easy? yep.
 
Cap'n Jack said:
Sigh. Please avail yourself of the on-line resources to see how a lead-acid battery works.
When you discharge a battery, you convert the sulfuric acid and lead oxide on the surface of the plate to lead sulfate and water- sulfuric acid is being removed from the battery and its concentration is reduced.

Now look up "freezing point depression".
When the battery discharges, sulfuric acid is removed. That reduces the number of sulfate and hydronium ions in the water. With fewer ions in the water the freezing point isn't reduced as much so the battery can freeze at a higher temperature (closer to the freezing point of water).

That's what "the Yankees have to do with it".

IMO, the freezing was the thing that pushed a probable weak (albeit working well enough) battery over the edge.

He seems to have a working battery now and that's what counts in the end.
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Ummm, I do believe he was making a joke about the "batter" instead of the "battery". Yeah, a smilie would have helped.
 
gprellwitz said:
Ummm, I do believe he was making a joke about the "batter" instead of the "battery". Yeah, a smilie would have helped.
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Ya know- that went right by me!

Thanks for clarifying. My reply edited...
 
smigaldi said:
Battery minder is now installed in the hangar!! Woo Hoo.
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As a point of reference, the battery in the Mustang didnt' have the juice to start it again after being parked for 10 days or so.

I have to put the BatteryMINDer on it.

It had the lighter plug drawing enough for an LED, other than the usual clock load.

I may need to get the battery replaced under warranty at Costco. Like yours it didn't handle being dead, dead very well.
 
mikea said:
I may need to get the battery replaced under warranty at Costco. Like yours it didn't handle being dead, dead very well.
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Lead acid's don't handle that very well at all.

in the winter the BMW M-Roadster does not get driven very often so I keep a BMW branded battery minder on it. It plugs into the cigarette lighter adapter.
 
Just a guess but I'll bet your battery was a Gill !. Hope you replaced it with a Concorde.
 
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