Alternative Power Systems

Nigel Hitchman · Post by **Nigel Hitchman** » Thu Apr 28, 2011 1:25 pm

there were lots of electric aircraft at Fredrichshafen, mainly self lauch motor gliders, but several conventional aircraft including an MC30 Luciole and a Cri Cri electric twin which holds a speed record of 260kmh or so. They think it can get to 300kmh soon! I dont know much about all of this, but the Cri Cri guy said he was using motors with brushes, which is not what most are using, apparently the brush motors are much more reliable. The motors were expensive, I think about 5000euro each and the two battery packs the same. The battery pack lasted about 25 min, but only cost 2 euro to recharge. The main problem I think being the number of uses you can get out of your 10000 euros investment in battery packs before buying new ones!
One surprise is that Yuneec werent there.

Ian Melville · Post by **Ian Melville** » Fri Apr 29, 2011 7:24 am

apparently the brush motors are much more reliable.

Not to the best of my knolledge. How can something with more delicate parts be more reliable? The brushes themselves arc and cause all sorts of issues. Was he refering to the controller?

What is supprising is that the brushless motors used by many in fullsize aircraft are in-runners using a small prop or reduction drive to the prop. An out-runner LRK motor is simpler and easy to build. The down side of any brushless motor is that the controller is is more complex and needs a good designer.

Nigel Hitchman · Post by **Nigel Hitchman** » Fri May 06, 2011 1:28 pm

Ian,

I found a few more details on the motors, they are brushed motors, manufactured by Electravia, a French company. They offer a 26hp, 35hp and 50hp motor. 50hp works out at just over 6000euro plus tax, while the 26hp is "only" 2700euro.
They have been flying with these motors since 2007in very light aircraft, motorgliders, trikes, paramotors and now the Cri Cri at 262kmh!
more details at www.electravia.fr

Ian Melville · Post by **Ian Melville** » Fri May 06, 2011 6:50 pm

Interesting, however is still don't see how they can be more reliable than brushless motors. However in the context or IC engines, both types are significantly more reliable, providing the electronics are kept within operating limits.

I got a lot of 404 errors trying to navigate the English pages

BTW those prices seem to be for the motor and controller only, you need to add a battery between 5 and 15 thousand euro, not to mention prop and mounts.

Interesting website with some good data
Thanks