Can I use the same battery for the receiver AND the electric ingnition on a gas four stroke engine?

It's not recomended, but it may work. It may cause your radio to have limited range. Most gas planes are large enough to handle a 2200mA battery with no problems. So, even if it will work, don't do it.

CCFPilot
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This practice is getting to be quite popular with some folks, while other like myself shy away from the idea.

Karol

You do read about more people doing it now, especially since 2.4 came out, but I still would not try it.

It can be done but you must use an electronic filter if you do so.
The only one of those that I use nowadays is the Tech Aero unit. there are a couple of others around but I have not had much success with them.


[link]http://www.tech-aero.net/ultra-ibec[/link]

What Voltage does your ignition require? If it requires more than 6 volts the Tech Aero unit is the only one I have found that will supply it reliably to the ignition.
If it is a simple "4 cell pack" requirement, then the weight saving is pretty negligible.

Even 2.4 can suffer from intereference. Don't ever rely on it to shroud a poor build or installation or product.

I use a single A123 pack with two leads (wrongwayrc.com) to power both the receiver and ignition on 3 50cc planes. Simple, clean, no issues.

No issues with range, not sure why anyone would feel that would limit radio range in any case.

Well, now even the moderator does it!

Seriously, I have been asking this for quite some time. I too have a A123 (LiFe 3200mAh) with 2 leads and I would also like to do this to save weight. But most told me not to do this

Ameyam

i am doing it on a dle 20 with no issues with no special devices..... i have other gassers that are not running this set up

Moderator, product reviewer, author, modeler for 25 ish years.

Only to give context because I hate posting "resume" type posts, but to give you the perspective that I'm not talking about my first big plane with no clue whats going on. I did avionics on Navy aircraft for a long time too so when it comes to radio equipment installation, I've got a pretty solid background.

1 2300 pack = 4 flights and charge. JR 921rx, 6x 7955 digital servos, and a DLE 55 ignition with a 42percent scale optical kill switch. Pilot RC Sbach, Pilot RC Yak, and Extreme Flight Extra.

I do step down the voltage going to the ignition with the reducer diode sold by WrongWay

Heck, even at conservative charge rates, they can be fully charged between flights if you want to.

I have 3 years of zero problems doing this with an IBEF. Have not tried without the filter so I cannot comment on that aspect of it. My only advice is that the reader needs to consider whether they are reading an opinion, or a report based on experience. Bye the way, there is no way the practice could reduce range, period.

I have 2 gassers running ignition power from the receiver pack(s). The important pieces are a good opti switch, making darn sure your ignition module is being fed the correct voltage, and don't even think about trying to do this on a AA size NiMh if you're using larger or digital servos, regardless of battery capacity or voltage. The NiMh battery chemistry is too wimpy to get the job done, period. That's the piece many leave out. I know because I learned the hard way, and those type lessons aren't soon forgotten!

I am doing it on a DLE 30 and a 72" Yak. I had a $80 3S LiPol with nothing to put it in. So I am using it with a reg and Y harness. So far no trouble.

David

Amazing how much mis-information there is out there, lol.

I personally won't do it any other way. Like Barracuda, I use a single 2300mah A123 that goes into a super switch on one lead (the super switch has two power leads that both go into the reciver if you wish) and the ignition for the other. A third lead is a charge lead. On the ignition side I use an optical kill switch and a simple volatage reducer. All products can be had from WrongwayRC...Rich is a great guy too.

I currently have this set up on a 71" SLick with 40 plus flights and it works flawlessly. The beauty of the A123 is you fly it a few times, hook the charger up to it and its done in about 7 minutes. No range issues, no interference issues, fly all day. (I use Spektrum 2.4).<br type="_moz" />

I decided I did not want to go to a123 batterys as this would mean a new charger and different battery chemistrys to deal with. I like nimhs, cheap and I can load test to see what is left in them, also have a few lying about. If every oz counted then for sure a single a123 sounds good but I still would prefer it to be isolated from the ignition vai some sort of filter.

I use two 6 volt 2100mah nimhs into two switches then into two seperate rx channels. This gives me full redundancy and doubles the availible amperage of a single 6v nimh.

I then use the tech aero ultra bec to supply a optically isolated and regulated 5 volts to my ignition, this alsoacts as a kill switch.

Prob would only recommend this for up to 30cc gassers.

Loads of differentways of doing thingsand geting the same results.

Is "noise" from the ignition modual goint into the receiver a real threat?

I'm using a Life 3,200 mAh battery that puts out a nominal 6 volts. Saito 20cc 4 stroke manual says to use 6 volts. Do I need more precise regulation?

That <font class="text10">"Tech-Aero Designs Ultra Ignition Battery Eliminator Circuit (U-IBEC)" sounds perfect and running receiver and ignition on same batt is not a new idea. But I like not to spend the $55 bucks if I don't have to. Is there a less expense way?

Thanks all for the very good info

Jim
Santa Fe, New Mexico
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My LIFE batteries put out 3.3 volts per cell, and peak closer to 3.5 volts for a while. 2.5 volts is the bottom. I am using the voltage reducer from Wrongway on all my LIFE-ignition setups. Not using the diode can harm 6 volt max ignitions, or so I have been told. I tend to err on the side of caution.

So, putting in an optical kill switch removed the chance of inteference if using a single battery? I am yet to wire my optical for a DLE20 on a Phoenix Extra and test flew without it. Now, this airplane needs to lose weight and one of the options is to use the LiFe 3200mAh battery as common to RX and ignition. I am using 9CAP with TM8 2.4 G module

Ameyam

A basic optical kill switch will NOT seperate your ignition from your receiver if you are using one battery, ahicks said above that he uses one battery with a opto kill im not sure what unit he is using but a standard rexel opto will not seperate a ignition from a rx using a one battery set up. Perhaps he can clarify.

I've been told they don't work before, but these, the ones I have, don't seem to be obeying that rule well. Both these systems have been run quite a bit and I trust them.

I'm using one 42% (basic) opti switch with power coming through a single diode so I don't have to worry about voltage. It's getting power from the receiver buss, which is fed by 2 6v NiMh batteries supplying power through 2 switches. It would work just as well if it were run by a single life, and I would go to 2 diodes for the A123. I'm using the 2 NiMh because I had them, I really like the idea of the redundancy, and because I'm running some 100 in. oz.+ digital servos.

The other setup is a little more off the shelf. It's from Syssa, they call it a "SAP Ultra IBE (Ignition Battery Eliminator) and Ignition Kill Switch". It features a built in voltage regulator, so you can run it as is with any battery chemistry you choose. The link is :

http://www.syssaaircraft.net/cart/pc...5&idcategory=2

I'm not here trying to talk anyone into this. I heard others were doing it and decided to try for myself. Other than the wimpy NiMh battery chemistry lesson I experienced, I've seen no good reason not to continue the practice. FWIW

Wrongway RC continues to supply ready to go components if you're shy about collecting them yourself. I understand he's also very supportive?

Yup the tech aero ultra bec and the SAP ultra IBE are the exact same product made by the same manufacturer, this is what I use.

It is different from a normal opto kill in that the ultra bec takes the control signal and ignitionpower voltagefor the ignition from onelead thatcomes from therx. this is opto isolated and filtered.

A normal opto isolation unit takes the signal vaione leadfrom the rx and is opto isolatedand thentakes a ignition powervoltage from a second non isolated lead that is meant to run to a independant ignition battery.

The problem is that if you use one battery and run that non opto isolated secondlead to the shared battery you lose any opto isolation you had! so whats the point.

Im sure ahicks knows the difference so just a heads up for anyone else new to this product

Million dollar question is it required in 2.4ghz.

Bought the reducer diod sold by Wrongway. $8 or $12 with shipping. Will that servie a smilar function to an "opto isolator" ? As I undestand, it should insure a steady voltage from my 3,200mAh Li-fe battery to my ignition on one lead while the rx is power by another lead. Or do I have something mixed up here? How do I acturally wire up the rx and ingition off one battery with the reducer diod in line?
Thanks for you help.

A regulator supplies a "steady voltage", a diode supplies a reduced voltage.

Like others, I'm not selling this setup, just confirming that I have used it reliably for probably several hundred flights. I live in Florida and fly year round, I fly nearly every weekend and I can work from the flying field so I'm there a LOT. I have 3 50cc planes as described above and they get a lot of flights in the course of the year. I have wrecked two planes in the last 3 years, one ran out of gas in a hover because I was having so much fun, and one flew into a hill when I turned off the transmitter in flight (the opto kill saved my engine btw), but I've never had a power system or interference problem flying this setup.

Yes, Richard from WrongWay will talk your ear off about A123's and aircraft power systems if you call and ask.

Headspace - No is the short answer regarding the voltage reducer. You would need the optical kill switch as well. It's what is actually allowing you to turn the power to the ignition module on and off with the radio. The diode/reducer would be installed in the line leading from the optical kill switch to the ignition module. This allows the kill switch to run on whatever voltage the receiver is running on and the ignition module the reduced amount, as power to it must pass through the diode.

Radar - I'm not as far into this as you might think I am. Your explanation of your concerns regarding optical isolation brought fresh understanding of what's going on there electronically. It raises the question of why this appears to be working so well without any (enough?) isolation? Not going to pretend I have the answer to that. I can only say I do actually have a lot of stick time run like this. Maybe it's 2.4, maybe the radio, dunno- but Thanks! -Al

I would hope others following would approach the methods discussed here with some caution. Obviously there's some controversy. Suggest somebody considering this might want to educate yourself well enough to make the call on how YOU want to proceed, then do that with lots of testing/range checks. I would not recommend what's going on here for a gas rookie getting ready to test fly his new 50cc plane. Get that down to where you know what you're doing, THEN make the call here.... you already have enough going on!

I think it might also be nice if others running like this would share their single battery experience/setups?

This question continued to bug me after writing the note above. I thought I had read somebody that knows a lot more about this than I do was using this process, so I did some searching. Here ya go..... posted a little over a year ago. Re-reading this makes me MUCH more comfortable running a single battery setup - or running from the receiver buss on a dual battery setup. Do as you like...

http://www.rcuniverse.com/forum/m_98...m.htm#10166524