Lipo's have a really useful, and interesting charge curve. When you get under say.. 3.1v per cell, there's essentially no power left in the cell. Nominal voltage for a lipo is 3.6v. Full charge is 4.2, but the meat of your useful power comes between say.. 3.9 and 3.4v per cell.When they measure the amp hours of LiPos, do they calculate to the low voltage limit (is it around 3.5 per cell or so?) or is it calculated to zero energy left in the cell?
Running a LiPo dead flat, then charging it, is a great way to form dendrites. I wouldn't recommend that you ever have that pack anywhere a sudden fire would unduly bother you.Lipo's have a really useful, and interesting charge curve. When you get under say.. 3.1v per cell, there's essentially no power left in the cell. Nominal voltage for a lipo is 3.6v. Full charge is 4.2, but the meat of your useful power comes between say.. 3.9 and 3.4v per cell.
To give you some idea of how little power is in a Lipo between zero and 3.0v per cell, I accidentially flattened a 6000mah pack last week. To take it from 0v to 3.2v per cell, took 250mah. To get it from 3.2v to full charge, took 6200mah.
His first flight (which has since been made private on YouTube) was done without gap seals between the wing panels. In the post-flight review Peter even mentioned the enormous amount of drag caused there but never made the connection to how the plane didn't fly well on those first crow hops. I suspect it's because the region behind the power curve isn't well understood by RC pilots.I want him to try a flight with the tape removed from the wings. I suspect he'll return to a wallowing nose high flight condition. .... now I type that, I think that sounds wildly unsafe.
I expect to see him at Oshkosh with a new design in a few years.He's exceedingly driven. He has time. He knows what "is enough" and doesn't get hung up on "perfect". He can ignore jerks. He's confident in his abilities. He has tools, and knows how to use them.
.... Very few builders have most of that. A large number of them are limited on time. Many more are limited on their ability to make engineering decisions. Others are obsessed with perfection. Others have budget concerns. Many are not able to stay focused.
That's were your other people are at.
you forgot to mention how much fun he is having.....star of his own video, a crew of supporters. I would guess he has a lot more personality than most of us.I think I probably flies better with the tape, but when he was test hopping in the middle of the night, I'm sure flying at an unlit airport with an UL would not be good for full tests since both are not legal. He made hops and proved it. I'm sure the new batteries that were not borrowed makes it much easier not to worry about buying someone else some new batteries. The question now is , this punk kid did it and on the internet, so why are all the experienced people behind?