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Lasar ignition and battery back-up from TCW

Barbeau

Barbeau

Member
Dear felows
During winter time I experiment starting difficulties due to batery low voltage at start up (batery is PC680).
I plan to install a Batery Back-up TCW to get right voltage at Lasar ignition unit when starting up.
Is somebody did such installation with Lasar ignition?
From TCW point of vue the 3 amps model is able to do the job (able to supply 5 amps in continue and 10 amps during 30 secondes).
Do you agree with that?
Thanks in adavance
Bernard
Venddée Air Park (France)
RV6A
 
I can't answer your question directly but I have a workaround that might help in the meantime. I had a LASAR EI on my previous RV-8 with a Concorde battery and a SkyTec LS permanent magnet (PM) starter. When starting, the large inrush current to the PM starter would bring the voltage down below that required for the LASAR EI to operate and the engine would be hard to start. What I learned to do is pull the LASAR circuit breaker and then engage the starter. After two or three blades go by, push the CB in while still cranking and the engine would start easily. After those first few blades the inrush current abates and the voltage comes back up above what is necessary for the LASAR EI to operate by the time the CB is pushed back in.

I did that successfully for several years until I got tired of it and replaced the SkyTec PM starter with a starter that drew less inrush current. Although I replaced the SkyTec PM starter with a Hartzell X-Drive PM starter and used it successfully (it was advertised to have less inrush current draw than other PM starters), starters with field windings have much less inrush current draw than PM starters.
 
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LASAR ignition

Hi Bernard,

Carl beat me to the answer I was going to give about pulling the circuit breaker before cranking the engine. My -6A used to occasionally do the same thing when the battery was cold, or starting to reach end of life.....the LASAR system would not start because of the initial voltage drop while cranking the engine. It never left me stranded anywhere, and happened infrequently enough it was not really a problem. I did recently replace the PC680 starter battery with an EarthX LiFePO4 (for weight reduction mainly) and it has not happened since. I am also about to change the starter (as Carl did) from a permanent magnet motor to a field wound type. But, starting problems are not the reason for the change.

So back to your airplane. If you do not want to operate using the circuit breaker OFF/ON trick, you could install a backup battery to run the LASAR system during engine startup. Your backup battery would need to be isolated from the main battery during engine startup. You would then want it to be in parallel with the starter battery during normal operation, so that it could charge from the alternator. If the backup battery and starter battery are simply installed in parallel, you still may have enough of a voltage drop during engine cranking to cause the LASAR controller to not fire the ignition. So there would need to be some type of switching (manual or automatic) built into your electrical system for this to work correctly. I am sure it can be done, but have not thought about all the details at this point.

I see from the TCW Technologies website an alternative you might want to consider. They make a power stabilizer device that is designed to prevent voltage drops during engine startup.
https://www.tcwtech.com/product/intelligent-power-stabilizer/
It looks like this may be a simpler electrical installation than the backup battery option, and does what you want it to do. I personally do not have any experience installing one of these, but these types of devices have been around for a while in the general aviation world.

Good luck.

By the way, if your -6A still looks like the images on the web.....nice paint job! Love the metallic red color.
 
I have been using LASAR system for 12 to 15 years.

Going from memory, I believe that the LASAR requires 9V for it to operate. IF your starter is pulling the battery below the minimum voltage required to start, I would suggest that it is time for a new battery. It is just a matter of time till you need a new battery to get the starter to work.

The SkyTec permanent magnet starter requires the most current. I replaced mine with a SkyTec NL starter years ago at overhaul time.

As others said, do not energize the LASAR ignition till after the engine is spinning if you are able to do that, it should work.

I am using the BUSH kit (or is it BRUSH kit) on my LASAR. In other words, the left mag has a impulse coupler and the right mag is my LASAR sensor mag so I am able to start my airplane without any battery.

The options above this post all sound like they will work. Which of the above options is best for you can only be determined by you. Me, I am reluctant to spend money for a back-up battery when that money could be put toward a replacement battery that is also going to be needed in the near future. An inexpensive battery tester would be nice to help determine the health of your existing battery. The one in the link was less money a year ago when I purchased mine.
 
Lasar starting difficulties

Thanks
contact TCW and to find the best solution.
I've heard of pulling the ignition breaker and back in when the propeller passes 2 or 3 blades.
For the time being, arcraft battery is connected full time to a charger to be sure to have it full. Problem could be when I'm outside my house.
I would rather have a real Lasar supply backup. the main advantage of a back-up battery like that of TCW is the possibility of connecting other systems such as the radio or the GPS which are thus saved
I've also heard of "Bush kit", but I don't know how it works and if it's available somewhere. I would have more about it but didn't find anything on NET.
Thanks for your advices anyway.

Stevea, I don't know wich photos you find on the net but this one was near Lisboa Portugal
8706977
 
LASAR bush kit

The “bush kit” for LASAR mags is simply this: the left mag has an impulse coupling in it….just like standard mags. So if the battery is dead, you can (carefully) hand prop the engine. And, if the LASAR control box stops working, the engine can still start (using the impulse coupling), and you can fly home in standard mag mode.
 
Lasar bush kit

On basic Lasar ignition there a Back up sytem wich prevent of power off or ECU faillure as well, but the engine must run. It doesn't work for starting procedure.
What is the difference with Bush Kit?
Do you know Bush kit is available somewehere?
 
Barbeau said:
On basic Lasar ignition there a Back up sytem wich prevent of power off or ECU faillure as well, but the engine must run. It doesn't work for starting procedure.
What is the difference with Bush Kit?
Do you know Bush kit is available somewehere?
Click to expand...

The BUSH KIT is two different part number mags. The IMPULSE coupling is added to the left LASAR mag. The TDC sensor is moved from the left LASAR mag and added in the right LASAR mag.

Would need to check with suppliers like Aircraft Spruce to see what LASAR mags and parts that are still available. The LASAR system and parts had a quadruple price increase a number of years ago. That makes me think the manufacturer would like to discontinue the product from lack of sales instead of just dropping support for it.
 
Barbeau said:
On basic Lasar ignition there a Back up sytem wich prevent of power off or ECU faillure as well, but the engine must run. It doesn't work for starting procedure.
What is the difference with Bush Kit?
Do you know Bush kit is available somewehere?
Click to expand...

I think what you are referring to is this: if the LASAR system loses electrical power after the engine has started, or the LASAR control box fails after the engine has started, the engine mags keep operating as it would with standard mags. The one catch is once the engine has shut down, it can not be re-started without an operating electrical system and an operating LASAR control box.

The bush kit, as Gary describes, adds an impulse coupling to one of the mags. This makes it possible to start an engine with a failed battery (hand propping) and start with a failed LASAR control box. The bush kit mags have a different part number than the standard LASAR mags. I do not know if it is possible to convert a standard LASAR mag to a bush kit LASAR mag.

As for new parts availability, here is what i know: the system is out of production and has been for many years. New parts are not available from Champion, even if they may still be listed on the Aircraft Spruce website. Factory support from Champion may be going away, or have already gone away too, not really sure. You can occasionally find used systems for sale here or on other aviation sales websites. There is a company in Kamloops BC, Canada that will overhaul the mags. Pro Aero Aviation. https://www.proaeroav.com/ I do not know if they stock rebuilt mags, or if they only rebuild them to order. (I have had them rebuild a set for me one time.)
 
Lasar ignition

Thanks to everybody
The Bush kit is the best way to have a complete engine start backup system with or without Lasar ignition that works well.
Since it seems very difficult (probably impossible) to buy a "Bush Kit", I decided to use TCW's battery backup (IBBS system). This will solve the starting problem due to low battery voltage but not starting without the Lasar ECU working well.
I will certainly take the opportunity to have one or two more back-up (VHF, GPS ...)
Thanks again, I wish you happy Christmas and very good 2023 year
 
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