More pictures of the RG24-11 inside the fabricated battery box.
I have been working on the battery box for the SF260 and which battery to use in it for 6 years. Yesterday I went to McMinville, TN where Chris Rounds has a T-34 restoration shop. His father "Don Rounds" is 65 and is an aeronautical engineer and has been working with me on the certification of the boxes and which battery to use. He was filling out a 337 on another modification for an A-36 bonanza.
I asked him how he stood dealing with customers who think they know what is best for their plane when they have limited background knowledge!!
I told him that in spite of the 6 years of work I had put into the battery problem each SF260 owner wants to solve the battery problem themselves. Don and I had wrestled with the two 25 amp battery problem for the T-34 for years until we settled on the RG24-11. We have serviced planes that had the two 25amp batterys in them. We have tested and retested each combination. The battery box with the RG24-11 is what we are putting in the T-34 when we replace the GE51C batteries. The RG24-11 is used on the A-36 Bonanza which has an IO-550 Continental engine. Yet people still want to use the two 25 amp battery system because some NON A&E salesman told them it would be good.
I spent 3 hours with the Concord salesman at Sun and Fun 5 years ago discussing which battery to use. His opinion was unequivocal --- the RG24-11.
I told Don that I have developed a lot more respect for Mike Patlin who has to deal with this "I want to invent it myself" mentality almost daily.
The following are my results from the battery work:
From: "Associated" Associated@telebyte.com
To: "Dudley Fort"
Subject: Re: the SF260 battery
Date: Thu, 15 Nov 2001 16:31:26 -0500
The Teledyne Gill G-639ES Battery is approved Per the Gill FAA PMA
Eligibility Drawing List #1516 Page 3. I don't know about a G-639AE.
Ours has the G-639-ES Mod.
Hope this helps.
Ben A Olson
The SF260W came with a GE-51C Gill Battery. The C stands for the Canon connector which has now been replaced with the Elcon connector. The GE-51C is a manifold battery that has two vents on top. One is for forced air and the other vent is for the forced air to escape outside. Since the battery weighs 55 pounds there is a hook arrangement on the battery cover so that the hold down bolts can be fastened after the battery is in place. Fig 2 shows this hook type arrangement. The hold down bolt has a metal fixture that slides down over the hook. I have seen this system fail so I strongly recommend the a cover plate or simply using the RG24-11M which does not have the hook but rather two holes. This way, if one of the hold down bolts fail, you do not have your battery tumbling away in the rear of the plane.
If you simply remove the Elcon connector the battery leads are exposed and bolt right onto the RG24-11M terminals. This battery will require spacers over the top of the hold down bar because it is 2 inches shorter than the GE-51C. You could thread the hold down bolts but removing them is a full days job.
Another battery for the SF260 is the Concord D8565/11-1. This is an RG battery and weighs 30 lbs. It has more than enough cranking power for the Lycoming IO-540 engine. This battery also has the hold down hooks on the top and should have the plate placed over the hold down bolts before fastening them down.
Here is the web site for the battery but you must have adobe-aerobat-reader installed to read the file. I have no idea how much the battery will cost but I can assure you that is is more than the $186 that you will have to pay for the RG24-11M.
http://206.171.106.212/Concorde/Drawing/MilitarySpecs/ValveRegulated/D8565_11-1.pdf
More shots of the D8565-11-1
Here is how you Safety Wire the Elcon knob in place.
This is a NiCad battery that weighs 60 pounds. The hold down knobs must be safety wired in place or the battery will work its way lose.
This fiberglass battery box can hold a RG24-11 which can then be wired to the Elcon connector. This is a nice arrangement if you want to have provisions for changing the battery quickly in case you forget to turn off the master switch. The battery box and connector and RG24-11 battery weigh 25lbs. With this battery box you do not need spacers for the hold down wing nuts.
Here is a picture of the hold down hook used on the heavier batteries. I think a bar placed across the top of the battery with holes for the hold down bolts to fit through would make this arrangement much safer.
Here is a close up of the hold down hook.
Here is a picture of the safety plate that can be slipped over the hold down bolts before securing them with the wing nuts. Also be certain to secure the wing nuts with safety wire. The safety wire does a lot more than just keeping the wing nuts from turning.
The older planes came with the battery box on the rear fuselage of the plane. This made them easy to get to and provided them with a safe compartment in case they broke lose during aerobatics.
This 27 pound battery can be replaced with the Concord RG24-11M which is a 28 amp battery. The RG24-15M is the same size and may offer more amperage but is harder to find in stock and does not work any better in the SF260.
The RG batteries do not require a vent since there is not free acid. However, military requirements do not take this into account and so the vent tubes must be provided on any battery used in a military aircraft. The fact that the vent tubes are unnecessary is not even up for discussion.
A note from Bill Vitale
Don't blame anyone for wanting to get rid of that old technology (and heavy!)
battery.
I have searched my file of Tech Documents and found only one SB (260SI-51
Dec. 1990) dealing with the battery. It describes replacing the original
obsolete battery with a new battery. Not a gel cell, I'm sure, as the new
battery weighs 25 KG!
My original battery was replaced with a Gill Gel Cell some years ago. I do
not have my documents here in Maryland but, as I recall, it was done through
a Form 337. Then, a couple of years ago, Don Brenner replaced the Gill with a
Concorde Battery. Not sure why he changed brands. No problems whatsoever.
Be sure to do a revised Weight&Balance.
Best, Bill
For Alternator and Starter repair:
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11619 ROUTE 76
POPLAR GROVE, IL 61065
800-397-8181