The Murphy Builders Site

I've been flying DJK since June of 1995... 19 years coming up quickly. I bought my first Gill 25 in 1994 with high anticipation of flight and it lasted almost 10 years... the next one 5.. the next one 3 and the last one won't even hold a charge for more than a few days, installed May 2012!

Even when they are new and fully charged, they have always cranked on first hit to TDC and stopped. Then hit it again and they'd start the airplane. Over the span of time I've had to have my starter rebuilt twice. Freshly charged.. when I hit the master on my volt gauge has always been slow working it's way to sweep up to 12 volts. Some days I even tapped on the glass....

I almost bought a new battery AND a "field" starter vs the permanent magnet Skytec I've had all these years, but Walter Klatt said try the battery first.

Finally got an above -10C day and some sun today to make it work friendly in the hangar. I installed an Odyssey PC925 today.. and the difference is like night and a BRIGHT day! I could taxi on the windmill effect alone and this was the battery right out of the box and already 5 months old. I checked it and it was only about 80% charged and figured I'd start there. On hitting the master switch the volt gauge snaps to attention now... and the cranking speaks for itself!

The old Gill Battery.. darn near dead albeit.

http://youtu.be/d6Tc1jWTZC0



The new Odyssey PC925 at about 80% charge.

http://youtu.be/e7MvQE1-MVM

Nice! I have the 625 in mine and have had no issues. Welcome to the modern world, Wayne! Craig

Wayne, is that really a PC925? If so, then yes, you could nearly taxi with it...LOL. It is the PC625 that I use, and it has plenty of power, too, and very light.

Yep... in the tail... I just looked for something that would fit and almost fill the same box the G-25 came out of!

Weighs 24 lbs... the Gill 25 weighted 21.15

Well, a little overkill,...haha, but yeah, don't think you have to worry about your starter anymore... And should be good for 10+ years. My old PC625 went for almost 13 years (started to lose some power at the end) before I finally replaced it with a new one I had sitting in the hangar for 2 years. And it, too, fired right up without having to charge it. They are indeed amazing batteries.

Wayne's scenario is almost identical to mine in the Long-EZ. I have used a GILL-25 for 26 years. The battery life seemed to get shorter and shorter the last five years as Wayne said. Soooo, just last week I purchased an Odyssey PC625 per a past post from Walter to replace my ancient technology GILL-25. The power, size and weight is amazing. Since the battery in the EZ is part of the C of G, I had to purchase extra lead to make up for the lost weight (in the nose) and made up a new positive cable with different battery terminal ends. No big deal there. Have not tried it yet, but if it works as expected, I will be a very happy peep! The plan is to use the same in the Rebel when the time comes. Maybe a dual PC625 setup in the tailcone or maybe a PC625 and PC680 ? Not sure yet.

For those interested, the factory tour on how the Odyssey Battery is manufactured is very interesting. Check Youtube.

And, yes, "I'll NEVER buy a FLOODED lead acid battery again!"

Terry R662

Actually these are lead acid batteries just not flooded.
Absorbed Glass Matt / Valve Regulated Lead Acid
Much lower internal resistance but they won't tolerate high charge voltage for long so make sure the regulator is not set too high.
Ken

Given the recent interest in these batteries, here is a good link from the factory, incl a comparison of the different models.
http://www.odysseyfactory.com/documents ... 6_0209.pdf

And for those in Canada, here is a link with good pricing and free shipping. And the PC625 is actually the cheapest of all the models.
http://saskbattery.com/ecommerce_157.htm

Aircraft Spruce Canada also has a pretty good price, but I think you have to pay shipping, and sales tax if bought local.
http://www.aircraftspruce.ca/catalog/el ... eydry2.php

In the US, batterymart.com usually has good prices.

Yes Ken, you are indeed correct that there's lead and acid in there, but unless something stupid happens the acid isn't coming out. No terminal corrosion or such either and you can mount them just about any way you want.

There is just such a huge difference in performance of these batteries that I didn't want anyone that hasn't installed their first one to waste time / money on a flooded Gill or Concord. I've been using AGM's in my Lund since 2007 to run my 275 Verado... the same huge buggers are still in there working just fine on season # 7.. hope they continue into season 8 onward.

As for the voltage.. I've been told the opposite.. they expect/need a higher charging voltage than conventional, than you would normal see with the typical old regulator of 13.8 volts. They like 14.1 to 14.7 as a charging voltage and if you go beyond that towards 15volts it causes the valves to pop open. You mostly need to be cautious of large portable chargers, so measure the voltage with the battery connected to be sure you're in the correct range before walking away from it.

Pardon me for asking, but is the rest of the electrical system up to par?
Corrosion (resistance) in the charging system wiring, or starter circuit.
Bad starter, alternator, regulator.
Just a few of the things that cause thease problems

Dick W.

Everything is fine Dick... the last couple Gill's you can have them fully charged and then come out two days later and it won't crank the airplane. Then throw a smart charger on them for a very short time and you'll get a green light that they're charged again and will start the airplane. I think the plates are touching in them or sulphating.. I wasn't overly impressed when I bought a new one in May 2012 and it arrived DOA with a cell that wouldn't charge and I got screwed around for 2 weeks to get a new battery and got stiffed the shipping twice!

I can start it.. fly around.. go park on a lake somewhere and it will start again a few hours later (albeit the same stop at TDC and then go on the second try)... so the charging system is working fine.. 14.2 /14.4 volts on the meter in cruise with radio, lights, strobes and landing lights on. I have a Honda voltage regulator, that although was a PITA to wire up compared to a simple Chrysler on/off, has worked like a charm for 18 years.

The Gill from day one has never gave a good crank and I think actually was cause for 2 bendix failures on my skytec PM starter. Thankfully they're an $11 Ford Van part..

As noted I put this Odyessy in, at only about 80% capacity and as you can see in the video it never even considered hesitating at TDC.

Interesting article in the latest Sport Aviation Mag. Sounds like his battery caused a lot of wiring corrosion which caused an electrical failure. He made some huge mistakes but maybe with an Odyessy he might not of ever encountered that problem.

I've been following a thread on Vans Air Force Forum for quite some time on the Lithium Iron Phosphate batteries. These are not the Lithium Ion batteries that have experienced quite a few problems. It looks like you can save 20-25 lbs for just a little more money, approximately $60 over the Odyssey batteries. The thread has developed over several years and they are getting quite a bit of experience with them. You can read it in its entirety here: http://www.vansairforce.com/community/s ... light=life. I'm seriously thinking about this for the Super Rebel.
Best,
Jerry Folkerts

Well Jerry, you definitely peeked my interest... did some work with Google and found this group as well.... StarkPower. Don't know a thing about them, but it is an interesting idea.. Even for my truck if you can believe their claims.

http://store.starkpower.com/products_by ... 9-1-1.html

Next link is for a $259 battery that weighs 2.5 lbs and puts out 600 CCA in a 21 Ahr battery. Is that possible? Ok lets dream... 80 gallons of gas weighs 480 lbs.... 480/2.5 is 192... 192*21 Ahr is ~4000 Ahr. Maybe we should be looking at an electric motor for our planes! LOL. (192*$259 = $50k ok maybe not). But its definitely worth considering, 1 not 192!

http://store.starkpower.com/12V21Ah-US6 ... _p_58.html

Rick Muller
SR70

Thanks for the link. I took a while to browse through the Stark website and these batteries look like a great solution for
some applications. One thing that concerns me is the following is a quote from the Stark website-Lithium 101-Lithium Cell Chemistry....

"Do not charge lithium-ion at or below freezing temperature. Although accepting charge, an irreversible plating of metallic lithium will occur that compromises the safety of the pack."

If I interpret this correctly that puts about a six month limit on the use of the Stark Lithium-ion Iron Phosphate (LiFePO4) battery where I live.
Mike B.