I have a 3W100QS where the ignition system is fed by a 1900 mAh/7,4V Duralite Plus battery through a Duralite 5,1 V regulator.

I have flown 60 flights and so far blown up two ignition systems.

Both cases are taken care of by 3W without any hassel by warranty claim, but I have got questions from 3W concerning the voltage level from the Duralites / regulator = 3W tends to belive that my setup gives a too high voltage = bad quality regulator.

Have any of you guys experienced this with this setup??

What I experienced both times is very short misfiring in flight followed by sudden stop of the engine.

Please give me your thoughts.

Kato

By chance, did you get the Duralites from them? Why mess with the ignition anyway. Seems to me that good ole 4.8v nicad or NiMh work just fine and in no way compromise your investment.
I just use my Sirius chargers when the batts have a few flights on them and don't have to worry about flameouts_bob

Well, I have Duralites all over the plane and want of course to stick to one type of batteries.

There should be many out there using this setup. Anyone else with good or bad experience?

best regards
Kato

Why don't you measure the voltage of your Duralite pack after the regulator using a good voltmeter? That should answer any questions about the voltage causing problems.

I have heard of late that 3W has had some issues with the new ignition module overheating. Possibly this is your problem. I AGAIN heard that 3W was sourcing a new "CHIP" which was more temperature tolerant.

Some users have had good results from utilizing the airflow through the cowl to cool the ignition module, believe it or not!

Duralight rates their regulators with a 1 amp load. I have their 5.6 volt regulators on some Li-Po from RadicalRC, and when I measure the voltage from the regulator it is 6.5 volts under no-load. Even with their 1 amp load attachment it is 6 volts when having a fresh battery. Remember, a fresh charged 5 cell pack can be over 7 volts right off the charger.

Maybe your voltage is too high because there isn't enough load from the ignition module to bring the voltage down. There is a new regulator out there that looks like it will regulate to a set voltage with or without a load. I think this is a much better idea. I feel the Duralite regulators don't do that good of a job if the need such a large load to get the correct voltage.

I will try and find the link and post it, but I would change to a 4.8 volt 1650 mah NiMh cell for now as a minimum and enjoy flying.

The overheating problem ison CH ignition modules. I don't know what 3W uses, but if you contact CH, the will fix the ignition very quickly. Great people to work with.

Mark

I have a 3w 50 on a 5.6 duralite reg with about 25 flights. I bench ran the engine for 2 hours with the duralites non stop, and had no problems.

Kent

Mark

I am aware of the C&H Ignition problem as well.

The problem I mentioned is 3W specific and has documented by several IMAC pilots thus far. Input from 3W reps concur on the temperature problem.

I don't believe there are any issues associated directly with Duralites regulators. I use them, my friends use them without issue at 6V on ignitions.

If you load the voltage after the regulator you'll find the voltage falls down to its nameplate rating. Measuring without a load is deceiving...

What about using a 4.8V regulator? I thought your suppose to strictly use only 4.8V on the ignition module, not 5.1 or higher.

Steven

For some odd reason the Duralite regulator with the lowest nominal voltage has rating 5,1 V. 4,8 V rating is not available, at least from them.

In any case I would find it very strange if the ignitions could not take a variation of at least 0,5 - 1 Volt. Most of the sensitive electronic components inside the ignition most likely are rate for much more than 4,8 V.

Kato

this is due to the duralight regulator being a switching regulator. Put even a tiny amount of load on it and it will drop down to approx. rated voltage. Just playing around I have found that the CH ignition on my 3.2 Sachs actually runs better (smoother and a couple hundred rpm better) when using a linear regulator on the ignition instead of the switching. The switching reg. that I had used on it was not a duralight reg. Possibly some ignitions don't get along well with switching regs. just like some Rx's don't. Or my situation may be just a fluke

But as far as burning up your ignition.i would have my doubts there. If you can rig up a way to measure the output voltage with the ignition turned on (not running) I imagine you will see that the reg. does what it is suppose to. It just needs a tiny bit of load to work.

Hi Kato,
I run the exact same Duralite Plus battery and reg that you are using. I'm am running on a DA IGN and it has caused no issues. I have not seen nor heard of any issues using this setup with IGN's. The 3w IGN's have had many problems over the years. They have had cap failures because of bad design, coils that would give up or become weak causing erratic running, misfiring, or dead cylinders, and the latest problem is with the units overheating. The overheating is not due to the battery or the regulator. It is another design problem. This is a known issue. They *should* cover the IGN and resolve this by fixing the underlying cause. Blaming the user and the battery system he is using is not gonna fix them.

Thank's everyone.

Duralite says that the regulator should read 5,06 V at 1 amp load. They also say that the 3W ignition (with blue dot / not the IIs) I have is rated for 6V.

I am now going to do a stand still and running test to measure no load and load voltage from the regulator.

However I really do not think this can be a regulator problem.

Kato