Re: [Paparazzi-devel] Multicopter new flight record 129min 37sec

[Sergey Krukowski]

Well, that's pity... I read that LiIons aint give their capacity if load  
is close to 2C. But in my setup the average current is about 10A, so for  
7P cells it's significantly less than even 0.5C load. That is where my  
suspicion about inaccurate current measurements came from. But according  
my earlier investigations with precise amperemeter my current data should  
be pretty good.
So, probably the cells are really not good enough.

Best regards,
Sergey

> Hi Sergey.
> Now that is along flight time for a rotorcraft!
> I don't think that your sensor is wrong, i have yet to find a battery  
> that
> delivers its
> stated capacity.
> Every cell i have tried usually fall short of its advertised capacity by  
> 10%
> Chris
>
> On Sun, Nov 2, 2014 at 5:39 PM, Sergey Krukowski <address@hidden> wrote:
>
> > Hi guys!
> >
> > Well, I finally done the new flight time record with my octo frame under
> > normal outdoor conditions.
> > The result is 129min 37sec. Well, it's not really way too longer, than
> > Ferdinands record, but the flight conditions wasn't very good today.
> > Partially was pretty windy.
> > The wind once even dropped my timer down from the logging installation  
> > box.
> > Looks like the NCR18650B cells in my battery are a bit old. Not sure if  
> > my
> > current sensor is 100% precise, but despite of the theoretical capacity  
> > of
> > 23800mAh, or, according the seller:
> > https://www.akkuteile.de/lithium-ionen-akkus/18650/
> > panasonic/panasonic-ncr18650b-3-6v-3400mah/a-100639/
> > the minimum capacity 3250mAh x 7 = 22750mAh, it gave me only 20230mAh.
> >
> > The attached logs are in rar file.
> > I'll upload the flight video on my youtube soon.
> >
> > Best regards,
> > Sergey
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