Battery Powered Transponder?

[jimboe]

My partner would like add a transponder and blind encoder in our NON-electric Champ so he can get flight following on his occasional x-country trips.

I'd really like to avoid buying and installing an alternator just to run a transponder once in a while. I know some of you use a total-loss rechargeable battery to turn your starters.

I was thinking there must be a rechargeable battery option to run the transponder. If so, I'd also like to connect it to our handheld radio (ICOM A22 - 12v), intercom (SP 400 TSO - 18v) and GPS (Lowrance AirMap 500 - 3v).

I'd want to be able to unplug the radio from the big battery if it goes dead and use the original Icom battery as a back-up.

Have any of you done this? Do you have any suggestions, recommendations or referrals?

Thanks,
Jim

[shep]

I am also thinking about going this route. There some "efficient" transponders (Becker, Microair and Garrecht) that were designed for gliders.
http://www.aircraftspruce.com/catalog/a ... ponder.php
My thought was just use the comm until I entered Class C/B airspace.
Another benefit is that the comm and transponders are relatively small - could probably be fashioned to fit in a glove box.

The downside is they tend to be $$$$

[joea]

The glider guys do this all the time, so its possible.

[Dennis]

Gee, it sounds like you want to run a full panel off a battery. Seriously, its the amps that you add up and deplete from your battery after converting everything to 12 volts.

What is the name plate amps and the name plate voltage for each device? If the devices require a voltage other than 12 volts as you indicate, you have now added another complicating factor to the equation. To run a starter or a com off a battery is one thing but to run a host of items requiring a different voltage is something else.

Bottom line, unless you know what you are doing when "mixing" voltages and sizing batteries as well as selecting type of batteries, you are asking for trouble. Keep in mind that a 12 volt 25 amp airplane/car battery is not the same as a 12 volt 25 amphour deep cycle battery.

Can it be done? Yes......but do you really want to?

Dennis

[pablo]

Advances in technology have made possible a lot of things: in medicine, for instance, you can swallow a little capsule with a tv camera that will take pictures all along the digestive system. Benefits to the patient are very little if any.
Aviation is not immune to the dreams of what is possible with new technology.

I, myself, enjoy my totally non electric 65 HP 7AC. Buying and installing a $3500 transponder will add over $100/hr to my Champ cost. If I MUST go to Airspace B or C, then I drive, or fly my Mooney.

Pablo

[bwmatz]

Check out this thread on the Taylorcraft forum:
http://vb.taylorcraft.org/showthread.ph ... ransponder

[joea]

Nice find Brian.



The above photo is from the thread that Brian posted and shows a portable avionics installation.

[Paul Agaliotis]

Jim,
Anything can be done. I would suggest against it. If your partner needs the electrical system buy a Citabria.
We have portables in the flight school planes with the total loss system and they work well. They also require constant battery maintenance. If the partner is intent on an electrical system change planes or partners.
Paul

[stknrdr]

Jimboe:

I run a SL30, KT-76A (w/encoder), Lowrance Airmap 600, and Sigtronics SP22N ICS off a small Gill battery under the front seat. I can also plug in my Sporty's handheld w/ VOR. Charged by solar panel on hangar roof and by BPE-14 turbo alternator when airborne. Everything works quite well. The total weight gain was right at 20 lbs, so I think you could come in around 11-12 lbs w/ only the xpndr and battery.

Both the SL30 and KT-76A were purchased used from Wentworth which cut the cost about in half. We have a lot of military traffic here and I like having the xpndr. A nephew flew C-130's here for several years and convinced me that the weight and expense were worth it, given the military operations in the area. The little cross countries my wife and I do are all under one approach control or another's coverage so we use flight following on a regular basis.

Go for it.

Tim

[Ed Clark]

I use a gel cell battery mounted with "temporary" mounts between the rudder pedals wired to a flexible solar charger that is velcroed to the dash rug. these are all wired to a radio shack 3 socket cigarete lighter attachment. It powers my ICOM A-24 using a battery eliminator from batteries america (avoids using normal recharge wire which eventually fails due to the wire "hanging down" pulling on the connecter); and my lowrance 1000 GPS.

I have pictures and can send them to anyone who would like them. All equipment is available as follows:

steve@batterystuff.com

Visit us often at: http://www.batterystuff.com/

PF6.5w $86.00 1 Power Flex 12 V 6.5 W Sunlinq Solar Panel

PS12120 $33.00 1 PS 12120 F2, 12 amp hour Gel Cell

Batteries America 800-308-4805 - Russ

http://batteriesamerica.com/newpage71.htm

CBE-210N: Battery eliminator for ICOM IC-A24, IC-A6, IC-V8, IC-V82, IC-U82 radios, etc. Part#: CBE-210N Manufacturer Part#: CBE-210N
(Qty: 1 x $24.95)

[jimboe]

Wow! Thanks for all the outstanding feedback. It is clear that adding a battery-powered transponder would take a little clever engineering and money.

I couldn't justify the expnse of leading-edge technology such as the Garrecht $3,000 transponder, but have seen used old-school Kings or Garmins for $800-$1,000. A gell-cell battery for $33 makes me very optimistic about putting a package together for about $1,500.

Paul and Pablo, I appreciate your positions and tend to agree with your philosophy of keeping a Champ light and simple. Nevertheless, I have a good partner who makes a reasonable argument for a transponder, not so much for entering class B or C, but because he'd like flight following at times. While my dream airplane is a Citabria, until the FAA grants them LSA status and someone else grants me a significantly larger paycheck, I feel lucky to own half of a Champ.

Brian, thanks for the link to the T-Craft forum. There is some great info there. My partner really liked the plug & play box and we'll check the feasibility of putting something similar together. Joe, thanks for posting the photo of the box.

Ed, I'll be in touch to get more details about the battery options.

I'm going to look for an avionics wizard to consult to make sure I pick compatible components.

If I can put an affordable battery-powered transponder package together I'll let you all know all about it.

Thanks again.
Jim

[Paul Agaliotis]

Jim,
It's nice to have all of the available gear. The problem is getting it installed and still being able to fly it with all the new clutter.
As for flight following, I was ferrying an AN2 to Oklahoma and requested Flight Following leaving Lancaster,CA. After about 15 minutes and 3 requests for my airspeed Joshua told me " no traffic on your intended flight path, radar service terminated." I was just too slow for them to fool around with.
Paul

[Roger Anderson]

Jim,
As for flight following, I was ferrying an AN2 to Oklahoma and requested Flight Following leaving Lancaster,CA. Paul

I'm a long time removed from that area as an ATC type. However, approach controls are few and far between out of LAncaster and east. Edwards approach use to cover that area....maybe still do. However, after them, it's just ZLA for many miles and they don't have very good coverage at the lower altitudes in that area.

[jimboe]

Wow! I see it's been 2 years since I started this thread. My airplane partner was the driving force behind it, though I was never very excited about the added expense and weight, so I procrastinated.

Tim was kind enough to send me a copy of a 337 for a previous transponder installation in a Champ and I was in the process of getting the field approval when I took some of Paul's advice:

"If the partner is intent on an electrical system, change planes or partners."

Well, 6 months ago I bought my partner's share of the airplane. My 1st order of business was to put the transponder plan on hold (my 2nd order of business was to get the auto gas STC from the EAA).

I'm still interested in improving the safety of flying so my current project is to buy a Zaon XRX traffic warning system and use a portable/rechargeable battery pack to power it (I'll start a new thread about that and will do photos and a parts list once I have it finished).

I prefer the Zaon approach to the transponder because I think it would be better to have a device on-board that warns me of nearby traffic and cut out the middle man (ATC). Yes, I know I'm supposed to be looking out the windows for traffic, and I am vigilant about it, but the reviews I read of the Zaon usually mention that it finds airplanes the pilot did not see on his own.

More about this project as it develops.

Jim

[joea]

I picked up a used PCAS unit at Middletown this year and after I finally learned how to work it really like it.

As well the ATC types could not believe that a 60 year old airplane could have something like this onboard.

Joe A