UL Power Engines Running on Alternator Power.

ULPower Aero Engines UK · Post by **ULPower Aero Engines UK** » Sat Feb 19, 2011 12:32 pm

Hi all

Just to keep folks Up to date on Information to dispel the rumour that the engine will stop if the battery fails.

The UL Power engines are electric dependant and run off the battery. The built in alternator also supplies power to run the engine. If the battery fails you are then running on alternator power.

For it to be able to do this you will need to have a 22,000uf Capacitor fitted after the regulator rectifier. The engine will run happily like this as long as the engine is running, obviously. The engine will also run happily on Battery power in the event of an Alternator failure.

I flew the other day and in flight turned the battery off via the battery isolator and she ran sweetly and did not miss a beat when the isolator was turned off and back on again.

I will be looking to do a flight with the Battery turned of for a longer period next time and will report back on my findings.

Previous without the capacitor and on running up ( on the ground this time ) I turned off the battery and the engine ran but erratically. With the Capacitor fitted, Idle at low RPM was smooth and uninterrupted when turning battery on and off.

All else going very well with the Engine installation in my Escapade and now coupled to a HercProp too.

Regards
Mark Jones
UL Power Agent. ( UK )

mike newall · Post by **mike newall** » Sat Feb 19, 2011 4:56 pm

A bit like P-Mag ignitions then.......

Rob Swain · Post by **Rob Swain** » Tue Mar 15, 2011 5:07 pm

This reminds me of a comment in the current mag about the UL engined Twisters.

If I recall the comment correctly it was that the builder wanted to avoid the weight of a second battery.
If it's a G-25 or something then I can see their point, but the second battery only needs to be a small fire alarm battery (1 kg or less) as all it needs to do is run the ignition, not the rest of the systems or the starter.

The second battery on a Leburg system is really quite dinky. Dave Mickleburgh reckoned that it would run the ignition for a couple of hours at least, more than enough to get the beastie back on the ground. And don't forget - this battery's life only became critical in the event both the primary ignition battery AND the alternator had packed in.

My comments here are not in any way intended to deride the UL engines's systems - I don't know nearly enough about them to be able to comment on them. I'm merely debating the comment made in the mag.
In fact I applaud the UL engine's designers for challenging the status quo and eschewing magnetos.