Battery/Ignition Problem

[Rogerck]

A couple of days ago, our 06SW had a low battery (not dead) and didn't have enough juice to start the engine. Low battery has never been a problem. Plane has steam gauges and was flown twice weekly over the last month. The battery and alternator switches were not left on and there was no obvious reason for the low battery. The voltage meter has been running in the normal range on recent flights. The plane does have the original battery. I wound up starting the plane with an additional battery. It started right up and the voltage gauge and ignition run up testing were all normal.

 

A trickle charger was left on the battery overnight. The battery turned the engine over at its normal high rate this morning. However, the engine was very difficult to start and only after a rest and advancing the throttle somewhat (which normally makes the engine difficult to start) did it catch. Again, the voltmeter read in the normal range. On run up, however, the number two ignition module lost 200 rpm and ran roughly.

 

I'd appreciate any suggestions on how to trouble shoot the ignition module problem. I'm also not sure if there is any relation between the ignition issue and the low battery. I'm skeptical about coincidences.

 

Roger Kuhn

[Roger Lee]

Hi Roger,

 

It is possible to have more than one issue, but as you say not very likely.(Most of the time :huh: ) A 200-300 drop is usually a plug, cap not on straight or bad plug boot connection. Bigger drops of 800+ are ignition modules as a rule and once in a great while go all the way back to the flywheel coils. With only a 200 drop your problem is after the plug coils. If you know which ignition module it is A or B you can look in the Heavy maint. manual and find out which four plugs go to that module and just change or look at them. When you remove them look for an electrode with a smaller than normal gap as this will also give you a 200 rpm drop. If the plug gaps are fine then change the plugs. If that doesn't do it then pull those four plug boot caps off and trim the wire back about 1/4" and screw the boots back on.

As far as the battery issue? HMMMM Sounds like something drained it and it doesn't really sound like a failed cell since it came right back. Nothing to do, but keep an eye on it. You can put a meter on it and turn everything off and see if there is any drain on on the battery. If your hard starting continues or progressively gets worse let us know.

[round_peg]

After the coils sounds like good news, if it works out that way.

 

How long should a battery be expected to last? If the CT battery is anything like automotive batteries, this one has been in service a long time. Hard starting = more drain under load. Age = not holding a charge as well.

[Roger Lee]

Batteries are funny. Depending on its use and frequency of use the battery life seems to vary between users. Some just have a bad cell and fail prematurely. I have seen some die in 2 years and some last 5 years. Most seem to be 3-4 years. It depends on how often it's flown or charged and how hard they get drained or how long they sit. Some of the CT's with the electronic panels have drains going on all the time, albeit small it is there. I have metered many and found low drains. We had one guy always leave his battery on a charger that Lockwood recommended for the CT. None of the rest of the other 6 at my field ever did. The one on the battery charge always had problems and went through a couple of batteries. No one else has ever had an issue until about 4 - 4.5 years and we all fly 1-2 times a week.

[round_peg]

Ours sat unused for several months, so that could not have helped. It sounds like we were already well beyond the expected service life in any event.

[FastEddieB]

I think a good, conservative approach is to replace the battery every two years whether it seems to need it or not. At the most, you're talking $100/yr - probably a lot less. Beyond three years you're on borrowed time, and for me it seems like false economy when the inconvenience, or even safety aspects of a battery failure are considered.

 

Right now, I'm at an advantage in that the battery removed from my plane (Odyssey 680) fits perfectly into two of my motorcycles, so the "probably-still-fine" battery taken from the plane usually goes on to provide years of service in the bikes.

 

Or, just keep the old battery charged and in the hangar to use as a 12v source or as a quick replacement if, for instance, you accidentally leave your master on and totally drain your newer battery.

[Jim Meade]

Ed, why buy a new battery every two years? Why not every year? Why not every three years? This mindless swapping out of components without regard to their condition blows my mind.

I'm tied up now, but why not post a reference to your battery manufacturer's maintenance and care instructions so we can all read it and discuss that.

Absorbent Glass Mat batteries are sealed and have maintenance and operating characteristics that are not like a car battery. It might be educational for us all to discuss them.

[FastEddieB]

Ed, why buy a new battery every two years?

 

Because it pleases me.

 

How often others do so matters little to me.

 

If you or they wish to investigate the topic of battery longevity in more depth, have at it!

 

 

[Doug G.]

I am mostly in Jim's camp on this one. I don't know how many times it has been said here..."it is only $__ a year." To misquote Everett Dirksen, "A hundred here, a hundred there, and pretty soon you are talking about real money."

[Roger Fane]

I am mostly in Jim's camp on this one. I don't know how many times it has been said here..."it is only $__ a year." To misquote Everett Dirksen, "A hundred here, a hundred there, and pretty soon you are talking about real money."

Both opinions could be correct. If you mainly fly around your local area, then replace as needed works well. However, if you take a long trip away from home, you might find the expense of a part failure to add up quite quickly, with hotel stays, shipping charges, or alternative travel arrangements. That battery that you keep on a charger in your own hangar, may just fail you when the plane is sitting on the ramp at an airport away from home.

[CT4ME]

My 2006 CT is still happily running an original battery. Well that's not exactly true because the battery was replaced at about 20 hours, but since then it's been running the same battery. Last week it fired up after sitting for over 2 months, no problems. 'Have never charged it. The two times I put it on the Battery Tender Jr, it went green in less than a minute, so I took it off. And not sure if this is good or bad, but this is Arizona, so the hangar is probably at least 100+ degrees about 110 days per year.

Tim

[Tom Baker]

Both opinions could be correct. If you mainly fly around your local area, then replace as needed works well. However, if you take a long trip away from home, you might find the expense of a part failure to add up quite quickly, with hotel stays, shipping charges, or alternative travel arrangements. That battery that you keep on a charger in your own hangar, may just fail you when the plane is sitting on the ramp at an airport away from home.

The thing is we are talking about a failure. A failure can happen regargless of the battery age.

[Jim Meade]

Here is a nice explanation of the battery shipped with the CTSW including maintenance recommendations. One thing of note is the recommendation that a float charger be used regularly. Here is an excerpt from the Contrails web site Maintenance section for this type battery.

 

SBS batteries are low maintenance items compared with

flooded batteries. Nevertheless, some maintenance is

necessary to ensure the battery is in good condition.

Installation and Maintenance activities should be recorded.

Record sheets are included in the Operating and

maintenance manual provided with the battery. A sample

record sheet is at the end of this section.

Below is a suggested maintenance routine. However, the

frequency of inspection and maintenance procedures may

vary depending on the criticality, number and location of

installations, equipment and commercial considerations.

Records

It is important to keep a written record of a battery’s service

life. The record is an aid in fault diagnosis and predicting end

of life. The record sheet should be kept with the battery so

its operating characteristics and service history is available to

anyone that works on it. Enersys may require the record if a

warranty claim is made.

Record sheets should be designed so that “trends” and

“sudden deviations” are easily noticeable.

Trend Data - can be helpful in predicting end of battery life

so that battery replacement can be scheduled and sudden or

catastrophic failures can be avoided.

Sudden Deviations - in bloc or string readings should be

investigated, it may be indicative of a cell or charger defect.

Readings

Every three months measure and record:

String voltage

Bloc voltage

Charger voltage

Charging current

Battery and ambient temperatures

String Voltage Readings

String voltage must be measured at the battery’s terminal.

If applicable, float voltage temperature compensation must

be taken into consideration.

String voltage = Number of Cells in Series x Float Voltage

Per Cell

Correct float voltage will maintain the battery in a fully

charged condition, recharge in an acceptable time and

achieve optimum life.

High float voltage will increase the rate of positive grid

corrosion, gassing, risk of thermal runaway and reduce

battery life.

Low float voltage will extend recharge time, not replace

internal losses and may cause degradation of the negative

plate leading to gradual permanent loss of capacity.

A discrepancy between the voltage measured at the battery

terminals and the charger voltmeter must be investigated.

If necessary, adjust the float voltage to the correct value.

Bloc Voltage Readings

Bloc voltages may vary within a string, but individual

stabilised bloc voltages should be reasonably constant.

The individual blocs should be within ±5% of the mean.

A sudden significant, or a small but continuous, deviation

from the bloc's stabilised voltage should be investigated.

Inspection

Inspect the blocs for dust, damage, leaks, loose or corroded

connectors. If a bloc or battery needs cleaning it should be

isolated and cleaned with a damp soft cloth.

Disposal

SBS batteries are recyclable. Scrap batteries must be sent to

a licensed recycling facility for disposal.

Scrap batteries must be packaged, transported and recycled

in accordance with local and national regulations.

A list of licensed recyclers and additional information on

battery disposal can be found on the web site:

www.recycle.net/battery.

Maintenance

www.enersysinc.com Publication No: EN-SBS-PG-001 February 2003

Battery Installation and Maintenance Record Sheet

Installed by: Date: Battery Type: Site:

Float voltage

[FlyingMonkey]

[shatner] The link is dead, Jim. [/shatner]

[CT4ME]

Nevertheless, some maintenance is

necessary to ensure the battery is in good condition.

... or not.... I've never touched mine in any way, and it's lasted for 6+ years. 'Still strong as ever.

tim

[FlyingMonkey]

I just got my airplane a couple of months ago, but it appears to still have the original battery. Mine was built in 2007 and only has 135hrs on it, so it has not been flown much per year, though I don't know what the maintenance was on it before I got it. I get strong voltages on the ground before engine start, so it still seems okay.