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Permalink Reply by Lee on July 1, 2012 at 5:19pm

Or this?

LiPo 13500mah XL Packs

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Permalink Reply by Jean-Marc Gendreau on July 2, 2012 at 3:01pm

If you are using standard 3DR or JDrones ESCs and motors, you can't use a 6-cell battery pack.  The voltage would be out of specs.  Use 3 cells or 4 cells battery packs only.

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Permalink Reply by emile on July 3, 2012 at 3:44am

You cannot use 6s lipos. Even 4s could be a little too much for those motors.

Regarding the video you should pay attention to the specs:

2 x 11000 4s batteries @ 820g each!

14x4" props

and 530kV motors.....

there is almost 1.7Kg only of batteries...

And yes flight time decreases with weight, so it is a matter of finding the best flight time to weight ratio. In some situations a 4500 mA 3s will be only a few minutes more than a 2200 mA.

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Permalink Reply by Lee on July 3, 2012 at 10:44am

I appreciate the info emile.  I have some research to do on power   :)

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Permalink Reply by jazztech on July 3, 2012 at 12:57pm

Lots of interesting infos on this rcgroups thread : 51min in the air

From my experience, good efficiency require big props turning at a slow pace. That's why Trad Helis are more energy efficient than multirotors, even with losses induced by gearboxes (<\troll) I have 7m30 flights with a tricopter using 880kv motors and 10x47 props vs. 12m40 with another tricopter using 11x47 props and 700kv motors, on the same 2,2Ah battery. Both tricopters weighting more or less the same. If you can't use bigger props for clearance sake, you can always give a try to 3-bladed props, which can be more energy-efficient than traditional two-bladed ones (3 blades vs 2 blades).

However, multirotors spends most of their time in the air at half throttle or slightly more, so the efficiency of the motor/prop/battery combination must be assessed at that speed.

Good luck, and keep us in touch !

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