12 b9
I have a Gill G-35 in the C182
I took it out and checked the battery voltage. It was down below 4.5
volts.
Aircraft Spruce wants $231 dollars for a new one.
The acid level was a little below the top of the plates.
I added a little water to each cell.
I hooked up the battery charger and very little current flowed. I
left it charging for 18 hours. Voltage is now over 12 volts and
charging current is 10 amps.
I was blown away. That battery sat around for years.
I'll learn more when I start the engine with it.
Paul Lamar
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Well I hooked everything up including my 200 amp battery charger. It
puts out 200 amp to aid in starting so it claims. It works on the
TTC engine.
In this case the O-470 engine turned over very slowly while the pre
oiler was running. The Gill measured over 12 volts just before I
tried to turn the engine over.
No question of starting.
It could be a lead acid battery that measures the correct voltage
will not put out the current. I don't know of this and never heard
about it.
Looks like I will need to buy a 12 volt battery from Walmart and see
how that does. The prop rotation was so slow I could have turned it
by hand.
After this was all over I checked the Gill battery again and it was
over 12 Volts. I am a bit mystified.
Paul Lamar
My Gill did the same thing, showed over 12 volts but failed on
delivering any amps, I used to have to hand prop the Pacer, once you
replace it your worries will go away. I also bought an el cheapo
cigarette lighter volt/ammeter on Amazon to see how the new battery
does, and it confirmed no voltage regulator issues and normal
current draw for everything except the landing light on my Pacer, so
there's a wiring issue on that circuit that I will fix when I next
have time
Alex Molteno
Paul,
I’ve found that my deep cycle trolling motor batteries would only
last about two years.
I also discovered that if I use a small charger called a “Battery
Minder” the interval would increase to about six years. It will
usually charge a battery back to 12 V within 24 hours if everything
is healthy. At that time it starts blinking showing that it is using
a pulse charge that supposedly destroys the sulfurdatian on the
plates. It was on special for about $39 at Northern Tool? Works
great for me. Barry Bordes
I have frequently seen batteries that will display their appropriate
resting Voltage level, but failed to produce their rated amp hours.
This usually first manifests by slow starting. For 12 V batteries,
the local auto parts place can easily test this function.
I have used the batteryminder device for over 10 years, which seems
to add at least one or two years to the life of aircraft batteries.
Scott Gettings
My inlaw put 30 AH Li-ion battery into his Toyota mini VAN. Weights
less than three pounds. It has build in safety to prevent damage
from full discharge.
In my mind much cheaper and safer than a old lead acid battery.
Henry Nee
We had something like that in the TTC for awhile and then it shorted
I think. Little tiny thing. Dan is a electric fan. He has a Tesla.
We were using my 200 amp battery charger to get it started. That
worked for a couple of months. Then for some strange reason the
engine turned over but it would not start. Turned out the Li-ion
shorted and dragged down the 200 amp charger voltage so the Motec
would not work any more.
Kind of opposite to a sulfated lead acid battery.
Took us a couple of weeks to figure that out. Took out the Li ion
and put the lead acid back in. Now it is starting again.
They are a bit weird and unpredictable :-)
BTW if your battery gets warm when you charge it that is a clue that
it is sulfated and you need the Harbor Freight charger.
Paul Lamar
Paul, and group Two battery items. First, a lead acid battery will
warm any time you charge it. In good shape it will warm less, but
that alone isn't an indication of sulfation. It can also be an
indication that you are charging the battery to fast. Kawasaki
motorcycles devotes some time to battery maintenance in all their
technical training classes. Yuasa sends them the information.
Slower is always better when it comes to charging. The Viking
charger Paul mentions is excellent, as is the "Battery Tender" which
is sold at Walmart for about the same price. Both have a float mode
that put a minimum maintance charge on battery while drawing
miliamps. Occasional use machines like planes or motorcycles can be
left hooked up and will always be ready when you want to start them.
Second, beware of the Li-ion battery for aircraft. It is enticing
since it is so much liter and smaller. However recently we had a
program at the Livermore CA EAA chapter 663. Since the chapter is in
the shadow of Laurence Livermore Labs they have a high percentage of
highly tech-savvy members. One invited a pioneer in the Li-ion
battery field to do a talk for one of the meetings. His comment, "I
would never run a Li-ion battery in my own plane."
The reasons are that if the battery ever internally shorts, which is
the primary means of failure in these batteries they will catch fire
and release a VERY TOXIC gas. If you have the resources of Boeing
you can build a successful containment so the plane won't be harmed.
In a small scale single battery use you could do it too, but you
would lose all weight advantages you used the battery for in the
first place. He also commented that this could happen with the
battery at rest while minimally discharging.
The technology has improved enough that it is now fairly rare for
one to just fire up, but it still can and does sometimes happen. If
you decide the risk is acceptable the best thing you can do is to
keep the charge above 30% at all times with 30-90% being ideal. He
gave us the quick lodown on the reason the Samsung Note 7's were
catching fire , He said that after reviewing the specs he would have
predicted it. He also said Apple bought their batteries from one of
the best, read safest, manufacturers although he uses an android
phone. All just offered as cautionary information not as absolutes.
Bill Jepson
An aviation supplier down here in South Africa was selling a Battery
Minder charger/maintainer and I purchased one. However it had a note
stating that it was not suitable for aircraft batteries. I notice on
the Battery Minder website that they do make an aviation specific
one ($240!) and that normal chargers will damage aviation batteries.
They actually have some "technical jargon" as to why. Not being an
expert in the electronics field, does this make sense or is it just a
case of "bulldust baffles brains"?
Pierluigi Ferro
Pier (if I may), I don't have any idea why the charger wouldn't
work. Note that the product I mentioned is a "BATTERY TENDER" not a
battery minder. I don't know if they are the same product. The Viking
from Harbor freight would also be good. I note that there is a
different version of the Viking suggested for Li-ion batteries, but
not for AGM or other versions of lead acid batteries. The arguement
sounds like baloney to me. Just be sure the charger doesn't charge at
more than about 2 amps and you should be fine. Bill Jepson
We have two people that have tested the Harbor Freight Viking on
aircraft batteries. Me and the Kitplanes guy. It worked for both of
us. You are on your own with other brands.
Paul Lamar
I'm going to weigh in on this battery stuff. And I am addressing
Lead Acid batteries, no other (e.g., NiCad, etc.).
The design of systems with a battery and an alternator|generator
is for the battery to "balance" the system. In general, the lower
the charge in the battery, the more the current generation system
can push (alternator or generator controlled by a Voltage
Regulator). The voltage regulator is sensing for the voltage to
hit (specified limit) of, say 14.2 volts for a "12" volt system.
Once the battery charge comes up close to the target output
voltage of the regulator -- if you have an AMP meter showing
charge/discharge, you will see the current flow start to tail off
to about 2-6 amps.
Now, when you start an engine and that battery has to put out,
say, 80 Amps to spin that engine, and you pull the charge level
down to where it would only measure, say 10V, a car or truck
charging system would immediately pump 30-40 Amps at that battery
trying to pull the voltage back to the target voltage (14.2V).
The battery will heat up because of the drain (current flow with
some resistance and we have W=I**2 * R - Watts = Current squared
* Resistance). Now we are causing the flow in the opposite
direction (charging it back up) and that same formula is used
again. So that battery is going to heat up.
Where this gets ugly is in places where the ambient temp is 95F
in the shade or better. That battery will get too hot. This is
why I couldn't keep a battery in my cars in the Dallas TX area
for more than 2.5 years before having to change them out. The
Heat there plus being inside the engine compartment basically
kills the battery.
Now for charging systems: 2Amp "trickle" chargers work fine for
holding Lead Acid batteries. You could probably get away with 6Amps.
Motorcycle batteries are another problem. Small engines that do
not use electric starters, are running a charging system to
operate the lights. Yamaha DT series bikes back in the late 60s
and into the 70s would blow the head lamp if the tail lamp burned
out because the small battery did not have enough load for the
system to keep that system from going to about 18V. The
headlights were not designed for that.
With starters, the batteries have to be larger and have a larger
amp capacity to turn the engine. Same charging system as I recall
(been gone from motorcycle mechanics and electricals for 20 years
now).
All of that to get to this: I call excessive semi-solid male
bovine exhaust on this Aviation battery charging stuff.
That Lead Acid battery has no idea if you are going to use it for
running a trolling motor, or operating a flying saucer. The rules
of physics are the same. V=IR, I=V/R, R=V/I -- Ohms law for DC
(where I=current/amperage, V=voltage, R=resistance).
I'll go back to watching and learning about the squish flow and
flame fronts. I'm still trying to get my head around the pressure
points.
Regards,
Steve Thompson
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