The International Cessna^® 170 Association

So my warranty replacement G-25S hasn't been holding a charge this winter and Saturday required a full hr to on the charger to get enough juice to start the engine. I called Gill this morning and they won't give me any warranty because the 2 year warrantly goes to the original battery I bought...that seems very customer unfriendly to me...and I followed the Gill instructions for intial charge and maintenance.

thinks it's time for another brand...

If you've a yen to become a bootlegger and live sort of on the edge, do as I used to do with batterys. Use a garden tractor battery with the proper oriented terminals, and replace it every year. They're cheap and fit a 25 size battery box exactly.
Of course, they do not have spill proof cell caps, so forget it if you do a lot of flying inverted.

I haven't followed your troubles but I have had issues with my G25. So much so that I spent a good deal of time talking (bitching) to the Gill rep at the 2011 AOPA Summit in Hartford. Basically, a one hour charge is not going to bring the battery back, nor is simply flying for an hour or two. If you haven't done so already, get a BatteryMinder(r) type pulse charger and leave it on the battery for about a month to SLOWLY desufinate. I did this with a similar charger and my battery has held it's charge ever since. It's been an additional year and a half so the battery is working on its fourth year No, I don't keep it on the charger, and yes, the charge has held all winter while I wasn't flying. Prior to that, it would lose charge after sitting less than a month which is what your sounds like it is doing. Hope this helps.

When people quit buying Gill batteries altogether, Gill might get interested in improving their quality. Gill used to make good batteries. The last Gill battery I bought was 10-12 years ago. Odyssey and Concorde make good quality batteries.

You're not saving any money if a new battery is needed every year or two.

I have to admit it publicly... I have quit using Gill Lead-Acid batteries because I value my battery box.
I now use Concorde VRLA sealed batteries. These batteries are FAA-PMA and are approved for isntallation in all models of Cessna 170 aircraft per Concorde STC# SA01118WI.

However, FAA AC 23-27 applies, which means that no STC approval is required or necessary.
See: http://www.concordebattery.com/otherpdf/TB9.pdf

One reason often overlooked for short battery life is parasitic drain. If you have a clock, or other "hot" items connected to your system it may drain the battery in even a short period as a few days. This sort of drain also contributes to "sulfation" which slowly destroys the battery.

To test for parasitic drain: Disconnect the NEGATIVE post of your battery (not the positive post, which is left connected.)
Install an amp meter capable of measuring 10 amps and also milliamps between aircraft Ground and the negative battery post. With the Master Switch in the OFF position, test for detected current at the 10A scale, (to avoid meter damage from high current-drains) then lowering the scale into the milliamps scales. Any parasitic drain will be displayed. A drain of 50 milliamps will drain the typical battery in only ONE WEEK! Eventually it will ruin your battery due to sulfation.

Keep your battery charged using a digital (quality) float charger at the correct voltage (13.2 volts). Sears has a $22 float charger which is inexpensive and contains the software to keep a float charge as well as "de-sulfate" a battery.
Sears Item# 02871219000 | Model# 71219

Watch out for those cheap battery minders at HF. I had one of them kill the 2 batteries in my race car in 2 weeks and a customer lost his race care shop due to the fire one started. I found that mine overcharged so I took it back and got #2 it wasn't much better just 1/2 volt less, but still nearly 14 volts. Go figure China junk...What I've done is put my good charger on it while I do the loading and pre flight. Pop it with 10 A for the short time. Worked this weekend after the 3 mo lay off. It had self discharged down to 11.5 volts before I started charging. My charger takes it to 13.2 and cuts back. I think the self discharge is the biggest problem with a battery that just sits.

We've discussed this before. Aircraft lead acid batteries use a heavier electrolyte than auto lead acid. The cut off characteristics of for discharging/charging is different than an auto lead acid battery. I personally would us an auto charger on my aircraft battery but monitor it manually. I would not trust the automatic features to act correctly.

• Battery Minder wrote:Why you MUST use an Aviation-Specific Charger!
  
  An aviation-specific battery is different than auto or marine types. To maximize the cranking amps and reserve capacity, while trying to minimize weight and size, aviation battery manufacturers use a higher specific gravity (SG) electrolyte in their aviation batteries. This "hotter mix" (more H2SO4 [sulfuric acid], less H2O [water]) means it will be overcharged whenever a non-aviation charger is used. Automotive chargers are set at a higher output voltage (typically 13.8 -14.6 volts) than aviation batteries can handle. The voltage settings and charge rates for aviation BatteryMINDer® models have been chosen after conferring with leading aviation battery makers in the U.S. We are the only approved manufacturer of maintenance chargers for use on all Concorde Aviation batteries.

  http://batteryminders.com/store.php?spa ... e&&app=air

gahorn wrote:Sears has a $22 float charger which is inexpensive and contains the software to keep a float charge as well as "de-sulfate" a battery.

The last few times I've been to Sears for anything, I have been thoroughly put off by their lack of customer service in several stores in several different states. Real shame, they used to be the go-to place. Last time I bought something there, the cashier acted like I was really a nuisance that she actually had to do something.

I converted to Concorde after my last Gill self-destructed while just sitting in the battery box in the hangar. A couple winters ago during a period of non-flying, I happened to go to the hangar and noticed the oil drip pan disintegrating from the acid that came through the vent tube. I have not had any trouble whatsoever from the Concorde sealed lead-acid battery (and I don't even have a battery minder on it). Average flying about 40-50 hrs per year.

I haven't had any issues with the Gills. Just replaced my G25 after almost 6 years of good service. I usually get 4-5 years out of these batteries with no problems.

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bigrenna wrote:Sounds like a great excuse to go with the Odyssey batt and loose a bunch of lbs in the process...

I had actually thought about that but decided I didn't want to go thru the hassle of changing battery box and getting FAA approval.

Strangely enough, I've been using the same battery charger on my automobile and aircraft batterys for sixty or more years and this is the first time I've ever heard of a difference between the two.

Like a number of you I switched from Gill to Concorde several years ago and at the same time went to the sealed type. I have had no issues with damage to my battery box or firewall as I did with the non-sealed Gills. A sealed Gill would likely have given the same results. I am on my second Concorde which is now about a year old. I didn't find I was getting any better battery life out of the Concorde unfortunately. Flying at least once or twice a month probably isn't helping battery life.

Now I find myself in a situation where my plane may have to sit for an extended time frame without being flown. I am going to replace the Aeroshell W-100 with Aeroshell Fluid 2F. The tech at Shell said that with 2-F in the engine its OK to fly up to 50 hours with the 2F in the sump, but not to fly for more than about 2 hours at any one time. He says that extended engine time with the oil hot can cause the antirust ingrediant to become thick and possibly not flow as needed. Strange! I have a new BatteryMinder Plus that I purchased from Auto Zone which was recommended by a fellow pilot who has been using one for quite some time with good results (he flies infrequently). I am hoping that this unit will maintain my battery during the planes' downtime without damaging the battery. It claims to maintain the proper voltage as well as desulfacate the battery as needed.

blueldr wrote:Strangely enough, I've been using the same battery charger on my automobile and aircraft batterys for sixty or more years and this is the first time I've ever heard of a difference between the two.

That's because you use automotive batteries.

(Seriously...it's true....aircraft batteries use a different S.G. electrolyte. However, the original vibrating-points regulators in our 170's ran a wider range of voltages than 13.2. Modern, digital regulators can do better...but unless you're running a solid-state regulator I doubt the lead-acid battery will appreciate the difference. I did re-calibrate my own vibrating-points regulator down to 12.8-13.0 volts and have had no problems with my Concorde.... but that little experiment has no "control" group for comparison, of course.)

MAybe it's a good excuse to get a batteryMINDer like some have suggested to see if I can bring it back...I'm looking at the Oddyssey as well, I've ask my mechanic if he's up for the paperwork challenge with the FAA.