Battery questions

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Mtns2Skies

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Mtns2Skies
Cessna 180, stock battery placement under baggage compartment. Lead-Acid battery. I fly atleast once a week.

The battery is only 8 months old (150 hrs of use) and it's starting to have trouble turning over the engine in semi-cold weather ~20-30F. Would a battery tender help with this? If so, can someone provide me a link to one?

Also - Can I hook up the battery tender through my external power receptacle? There is a fuse box protecting the system.

https://www.aircraftspruce.com/catalog/elpages/plugnjump.php?clickkey=14728
 
If you're using an old-school flooded battery? Add a battery warmer to your preheat routine. Or dump the old and go AGM. They work MUCH better in the cold and don't lose charge during inactivity.
 
Stewartb said:
If you're using an old-school flooded battery? Add a battery warmer to your preheat routine. Or dump the old and go AGM. They work MUCH better in the cold and don't lose charge during inactivity.
Click to expand...
Yep, old school flooded battery. Do you have a link to a battery warmer? I'm battery illiterate, What's AGM and do you have a link to one? does it just drop into my old battery box or do I have to replace the box?
 
You can use a heating pad as a battery warmer, if you have power nearby (I forget....are you in a hangar?)
AGM - Concorde is the best choice. Just a drop in to your battery box. Like changing out the batteries in a flashlight - same size and style, just better.
 
Yes I use an automotive battery blanket and a batteryminder in the winter. Rapido starts.
Not all batt boxes have room for a blanket, I am thinking about using a low wattage ie 25W pad under another battery of mine.
 
Mtns2Skies said:
The battery is only 8 months old (150 hrs of use) and it's starting to have trouble turning over the engine in semi-cold weather ~20-30F.
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Something else to consider is to check your electrical system for any parasitic drains in addition to the cable condition/connection at your battery, airframe ground point, start relay, starter, and the ground interface for starter/relay. If the sparks don't flow right it can lead to similar problems with new batteries. Also most battery manuals contain specific info on battery storage, charging recommendations, usage rates, etc. that will give you a base line to follow in your search.
Mtns2Skies said:
Can I hook up the battery tender through my external power receptacle?
Click to expand...
In most cases it's better to connect right at the battery. But you could add a charging harness like some Concorde chargers have that connects from your battery to a separate plug which could be located in the same area as your EP socket for easy access.
 
Clean the battery terminals and put a little white grease on them before you put them back on.
Connect an amp meter and check the current draw with the master off. Should be only a few milliamps from the clock.
Check the charging voltage.

If a battery tender makes a difference when sitting a week, either your battery is a real POS, or there is something sucking electricity even with the master off (more than just your clock).

My 5 or 6 year old battery cranks like a sumnabitch when it is 20-30 out and the airplane has been sitting for a month or two with no "tender". But it's not an "aircraft quality" battery.
 
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In older airplanes (and that 180 is getting plenty old, even if it's the last one built) I have often found the master and starter contactors defective. They have massive copper contacts in them, and as they cycle they make sparks and suffer burned contacts, and as they age (years) the contacts oxidize. Both factors introduce resistance that you absolutely cannot afford. A starter is going to draw at least 250 amps. If we encounter weak starting, the voltage at the starter has probably fallen to 6 volts or so Instead of the more usual 10 (due simply to finite battery capacity), meaning that we have a drop of four volts at one or both contactors or in some connection between the battery and starter (which includes both positive and ground paths). Let's see: E=IxR, so 4=250x.016. That's 0.016 Ohms. Very tiny resistance. See what I mean when we say we can't afford resistance? The normal small resistances in cables and ground paths is bad enough.

Many, many batteries are replaced unnecessarily because the engine doesn't crank enthusiastically. There are smarter ways to deal with this and I have posted them here before. Aviation is way too expensive to just start blindly replacing stuff. Troubleshooting involves measuring voltage drops across the contactors and various connections, including the engine-to-airframe ground path. Measurable voltage drops when the engine is cranking is cause for cleaning connections or replacing corroded cables or bad contactors, and the contactors are most often at fault, followed by dirty ground straps and the like. With a voltmeter a mechanic can pinpoint the defect, and his first move is to rule out bad contactors by measuring the voltage drops directly across their terminals while the engine is cranking. He should see zero volts there when cranking. If they have resistance he'll see some voltage.
 
If I was you? An Odyssey PC-925 would go in. Minor alteration per AC43.13-2B chapter 10. Much better battery. My Wagon has a PC-625 on the firewall. Never needs a charge or preheating.

You can get a silicone heat pad at any industrial store. I agree that 25w is plenty. I think Tanis and Reiff still sell battery warmers. Probably cheaper ones could be found at O'Reilly's or NAPA.
 
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Concorde AGM made all the difference in turning over my big bore beast. I highly recommend it.
 
Mtns2Skies said:
Cessna 180, stock battery placement under baggage compartment. Lead-Acid battery. I fly atleast once a week.

The battery is only 8 months old (150 hrs of use) and it's starting to have trouble turning over the engine in semi-cold weather ~20-30F. Would a battery tender help with this? If so, can someone provide me a link to one?

Also - Can I hook up the battery tender through my external power receptacle? There is a fuse box protecting the system.

https://www.aircraftspruce.com/catalog/elpages/plugnjump.php?clickkey=14728
Click to expand...

I’d go with a battery minder (12 or 24v) and use the supplied quick connect ring harness direct to the battery.

I’ve been using the 24v version with great success, whenever the plane is in the hanger it’s plugged in.

https://www.amazon.com/BatteryMinde...=2025&creative=165953&creativeASIN=B01D3SWXUA
 
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A battery minder on a cold battery isn’t very effective. You’ll still need to warm it up to make it sing. Cheap solution if the battery is otherwise healthy.
 
Your new lead acid battery was just strong enough to crank your engine in warm weather, colder weather equals colder oil, which requires more cranking power, and your normal system isn't up to the job,, Pre-heat.

Battery tenders are never a bad idea.
 
Tom-D said:
Your new lead acid battery was just strong enough to crank your engine in warm weather, colder weather equals colder oil, which requires more cranking power, and your normal system isn't up to the job,, Pre-heat.

Battery tenders are never a bad idea.
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I do preheat. Engine stays 80F or above. The battery gets cold soaked being in the baggage compartment.
 
Stickman said:
You might consider a firewall mounted lightweight battery. I've got one and it works very well, shorter cable runs by 10-12 feet and takes something like 17 pounds off of the airplane.
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Winner, winner chicken dinner!
 
Stewartb said:
A battery minder on a cold battery isn’t very effective. You’ll still need to warm it up to make it sing. Cheap solution if the battery is otherwise healthy.
Click to expand...

How so?

If you’re always plugging the minder in after flying, it works quite well, or at least that’s been my experience with the cold weather and my skywagon.
 
Probably didn't need it? Cold batteries don't charge well unless the charger is temperature adjusted.
 
Stewartb said:
Probably didn't need it? Cold batteries don't charge well unless the charger is temperature adjusted.
Click to expand...

The batter minder (not tender) is auto temp adjusted
 
Well you must just be extra special. No minder needed with modern batteries. ;)
 
Dan Thomas said:
In older airplanes (and that 180 is getting plenty old, even if it's the last one built) I have often found the master and starter contactors defective. They have massive copper contacts in them, and as they cycle they make sparks and suffer burned contacts, and as they age (years) the contacts oxidize. Both factors introduce resistance that you absolutely cannot afford. A starter is going to draw at least 250 amps. If we encounter weak starting, the voltage at the starter has probably fallen to 6 volts or so Instead of the more usual 10 (due simply to finite battery capacity), meaning that we have a drop of four volts at one or both contactors or in some connection between the battery and starter (which includes both positive and ground paths). Let's see: E=IxR, so 4=250x.016. That's 0.016 Ohms. Very tiny resistance. See what I mean when we say we can't afford resistance? The normal small resistances in cables and ground paths is bad enough.

Many, many batteries are replaced unnecessarily because the engine doesn't crank enthusiastically. There are smarter ways to deal with this and I have posted them here before. Aviation is way too expensive to just start blindly replacing stuff. Troubleshooting involves measuring voltage drops across the contactors and various connections, including the engine-to-airframe ground path. Measurable voltage drops when the engine is cranking is cause for cleaning connections or replacing corroded cables or bad contactors, and the contactors are most often at fault, followed by dirty ground straps and the like. With a voltmeter a mechanic can pinpoint the defect, and his first move is to rule out bad contactors by measuring the voltage drops directly across their terminals while the engine is cranking. He should see zero volts there when cranking. If they have resistance he'll see some voltage.
Click to expand...

Dan, how and where do I hook up my multimeter to check contractor voltage drop?

The AGM I replaced on my plane was 9 years old. I replaced it on advice from my A&P. New battery didn’t do much for the cranking hesitation (it helped some). At annual, one of the contractor terminals was found to be loose.

I’d like to be able to troubleshoot some of this myself...
 
Stewartb said:
Well you must just be extra special. No minder needed with modern batteries. ;)
Click to expand...

Nope, just batteries being batteries, and I don’t fly when it’s crazy cold outside, which can span some time
 
Normal 12v battery resting voltage is about 12.6v. If its much less than that you could have a cable/connection problem somewhere. I would expect that any battery bought in Wisconsin to last at least 24 months before showing aging.
 
A Concorde AGM battery will have little self discharge and performs well when cold. I'll never install a flooded cell battery again.
 
455 Bravo Uniform said:
Dan, how and where do I hook up my multimeter to check contractor voltage drop?

The AGM I replaced on my plane was 9 years old. I replaced it on advice from my A&P. New battery didn’t do much for the cranking hesitation (it helped some). At annual, one of the contractor terminals was found to be loose.

I’d like to be able to troubleshoot some of this myself...
Click to expand...
This is a good start at troubleshooting the health of your starting system
https://skytec.aero/aircraft-starter-performance-issues/
 
If you have not checked the manual for your flooded cell battery and followed the prescribed MX it will not last.

Flooded cell batteries require some TLC. If you are willing to perform the TLC they will generally outlast AGM (absorbing glass mat) and also provide a greater warning of impending failure.

AGM by it's very nature it less tolerant of heat and vibrations. As you discharge a battery you generate some heat, which also causes some water in the electrolyte to become gaseous. The glass mat absorbs the gashes and holds them till recharging. However this has a finite capacity, if you exceed the capacity the gasses are vented. With the battery sealed there is no possible way to restore the lost water/electrolyte.

In addition AGM by being sealed you are more limited to testing or checking the battery health.

However, if you do not want to perform the MX, AGM is the way to go.

Further flying that much, unless all your flights are under 30 minutes the battery should have recovered its charge from starting. This screams that you have something draining the battery or bad connections
.





Sent from my SM-J737T using Tapatalk
 
I forgot to mention. See if your mechanic has a desulfination charger. This may "save" your existing battery.

Sent from my SM-J737T using Tapatalk
 
tspear said:
I forgot to mention. See if your mechanic has a desulfination charger. This may "save" your existing battery.

Sent from my SM-J737T using Tapatalk
Click to expand...

I sound like a paid advertisement lol
But battery minder has desulfurization
 
James331 said:
I sound like a paid advertisement lol
But battery minder has desulfurization
Click to expand...
Depends on the model, if a straight tender than no. The straight tenders are much cheaper. Hence why I split it off.

Sent from my SM-J737T using Tapatalk
 
tspear said:
Depends on the model, if a straight tender than no. The straight tenders are much cheaper. Hence why I split it off.

Sent from my SM-J737T using Tapatalk
Click to expand...

Battery MINDER is not a tender, different box

942x_128CEC1_BatteryMINDer_12v_2_4_8_Amp_Charger_Maintainer_Desulfator.jpg
 
So often the cables are to blame. When I bought my Saratoga there were multiple entries every 12-18 months of “new Gill battery”. The current Gill was around a year old and it wasn’t starting the IO-540 with much pep.

I checked the cables and they sucked. The old braided ground was green with corrosion. I spent about $200 on a battery box mod and copper ground from bogart. Night and day difference.

Might be your battery but it wouldn’t be my first thought. With a solid electrical system a good battery should turn that engine with ease even in cold temps.
 
James is corrrect. The Battery Tender is a cheapie and the results are not good.
The Battery Minder is what you want.

Cheapout? Well you'll be buying batteries....every other year.
 
7326CD18-B5F8-495C-8058-63423EE8322C.jpeg My Cessna has used an Odyssey PC625 battery mounted on the engine side of the firewall for 20 years. I have never used a battery charger to maintain the battery. It has been mothballed several times between fall and spring by changing oil to anti rust preservative oil and parking it outside. In every occasion where I returned it to service in spring I did nothing but prime the engine and engage the starter. The motor spins to life every time. No maintanance charge required. In winters where I do operate the plane it will get engine preheat using a Reiff system for a temporary period prior to the flight. No battery preheat is provided. The battery has never failed to easily turn the engine to start. Stickman’s earlier post was correct. When I changed from stock battery to the firewall Odyssey my airplane lost exactly 17# and the starter became more responsive due to very short cables. MLJ Aircraft at Birchwood, AK produces the best firewall battery box for a Cessna that I know of. That’s what I have and it fits an Odyssey PC625 battery while the other STC boxes use the SBS-J pma battery (same as the PC680 non pma ). People are stubborn and cling to the idea that an airplane needs an “airplane” battery. That is not true and AC43.13-2B chapter 10 provides guidance on that topic. I’ve enjoyed a better battery in my plane for 20 years. Less weight, better cold weather starting, holds a charge for longer than I need, and really incredible durability during a couple if years where my alternator was acting up. FWIW, a buddy wanted more battery duration in case of alternator failure in his 180 so he mounted a PC925 under the passenger side floor. It was a very tidy installation.

My plane hasn’t been started since October. In a week or two I’ll dig it out of the snow and fly it to my new hangar to put skis on and get on with winter flying. If temps warrant preheat I’ll hook up a generator and do it. After that, the battery will spin my motor to life just fine, just like it always has. That’s a pirep.

My battery minders are for 4-wheelers that have a parasitic load. My airplanes don’t need minders. Well, I put battery disconnects on my wheelers so they don’t need minders anymore, either. My maintenance chagers are in a box in the garage. Don’t need ‘em.
 
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baboss said:
This is a good start at troubleshooting the health of your starting system
https://skytec.aero/aircraft-starter-performance-issues/
Click to expand...
That there covers most of it. I would only correct one thing: Check the voltage drop, not the resistance, between the battery negative and airframe. As I pointed out earlier, even tiny resistances matter where so much curent is involved. E=IxR. It takes an expensive meter to measure tiny resistances, but even a cheap meter will measure voltage drops.

Note that all voltage drop readings are taken with the starter cranking the engine. Without large current flow, any readings are meaningless.
 
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Dan Thomas said:
Check the voltage drop ... between the battery negative and airframe.
Click to expand...

I’ll take the hit for the team on stupidity - do I measure between the ground cable, with one test lead on the negative post and the other on the frame mount?
 
Pardon the drift, but next time you change your battery, you might be able to save some weight with the Odyssey.
 
455 Bravo Uniform said:
I’ll take the hit for the team on stupidity - do I measure between the ground cable, with one test lead on the negative post and the other on the frame mount?
Click to expand...
Yup. The black lead on the negative battery post, the red on the aluminum next to the frame mount. Might have to scuff a clean spot on the aluminum to get good contact for the probe.
 
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GeorgeC said:
Pardon the drift, but next time you change your battery, you might be able to save some weight with the Odyssey.
Click to expand...

I plan to pre-emptively just for the weight loss... but i have a miniscule useful load, if i had a larger one id just do when current one goes...

To OP, did the previous battery give a good service life? If not it adds credence to those saying it may not be the battery...
 
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