Replies to This Discussion

ModeratorPermalink Reply by Alex on April 9, 2011 at 10:52am

The electric motors use most of the battery

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DeveloperPermalink Reply by Doug Weibel on April 9, 2011 at 1:59pm

Your theory is almost certainly false. APM will use more power than an RC receiver. There is no magic to having APM control servos and a speed controller. The servos and speed controller will use the same amount of power if receiving control signals from APM or a RC receiver. And, as already mentioned, the propulsion system uses 90+% of the power anyway.

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Permalink Reply by Fabien Bruning on April 9, 2011 at 2:08pm

Easiest way to extend flight duration is to enlarge your wings and buy a bigger battery. Using an Easystar with Easyglider wings and a 4400 mah battery gives flight times over half an hour, and I suspect a lot longer if you make careful use of the wind.

 

Theoretically you could stay up indefinately on thermals!

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Permalink Reply by Ritchie on April 9, 2011 at 2:40pm

Propulsion as already mentioned is the life sucker. Planes last longer than quads and copters because they have less motors (usually).

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DeveloperPermalink Reply by jasonshort on April 9, 2011 at 4:49pm

APM will more aggressively work the servos compared to a human pilot. That's a lot of extra drain right there. But it pales in comparison to the main motor. I can fly my stock easystar for 30 min with a newish 2100MaH battery. With all the AP stuff, about 25-26 minutes. If I fly on a slope, I can fly indefinitely.

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Permalink Reply by Jeffry Work on April 11, 2011 at 2:25am

Wow, you guys are really open my perspectives. Thanks everyone.. =)

 

@Fabien Bruning, where can I get that 4400 mAh you're talking about?

 

@jasonshort, if I use two of 2100 mAh batteries, will it theoretically take me fly for an hour?

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Permalink Reply by Fabien Bruning on April 11, 2011 at 2:47am

United Hobbies, where else! http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=...

(their A-grade is a wee bit more expensive, though I suppose that's a better idea)

 

Theoretically, if you double the battery capacity, you'll also increase the weight of the plane and thus decrease the flight duration. There's an optimum relationship between battery capacity and flight duration for every airframe, I wouldn't know how to calculate it, though that's the proper thing to do.

As a mechanical engineer I say take the biggest airframe you can find, put on an engine and stuff it with batteries till you reach an hour ;)

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Permalink Reply by Andrés on April 11, 2011 at 8:35am

Fabien,

 

I gave the problem of optimizing battery capacity to achieve long flight times some thoughts and found a very simple solution. You are right, in the point that the problem depends on many airframe parameters, but choosing the optimal battery capacity turned out to be a lot easier than I expected :D

 

Regards,

 

Andrés

 

 

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Permalink Reply by Jeffry Work on April 11, 2011 at 9:10am

@Andrés, the calculation in the pdf is really2 complicated for me, but the short & simple calculation formula is very much helpful. Thanks! =)

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Permalink Reply by Jeffry Work on April 11, 2011 at 9:06am

Many thanks, Fabien! =)

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