07-11-2012, 01:53 PM
(07-11-2012, 01:43 PM)Flying fisho Wrote: As I time my flights to reduce cells no lower than 3.8 v to preserve battery longevity, under load what could I expect a battery voltage to drop to at the end of my flight. Theoretically speaking of course. And would that verify a 3.3v average?
That is a very good question Wayne and it depends on the amount of current your drawing and what the internal resistance of the cells are. Sometimes one cell has higher internal restance than the others and it will drop the voltage of the whole pack (because it's in series) I have a few packs that I purchased at the same time from the same place and they are different from each other under load.
What you can do is put a meter on them and test tem on the ground. I usually bring my meter down to the field when I'm there. Samste nearly allways has one with him as well. Do it with a fully charged pack and after your normal flight and you can see the difference and get a feel for what happens.
That's basically what happins with my radio beeping, I have the telemitry set to alarm at a certain minimum voltage around 3.6 V per cell first alarm 3.4 V per cell urgent alarm. You will have noticed it on the flight line. Beep beep beeep ect as soon as I back off the throttle the alarm stops, because the pack voltage goes up again. I can draw enough current to urgent alarm a fully charged 12S 3000 pack with my big Yak but this is in "10 second burst" mode and I only do it for a few seconds usually less than 5 seconds.
“The knack of flying is learning how to throw your machine at the ground and miss.”
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