I would agree that batteries in the smaller sizes (in the sub 1800ma range) the higher C-ratings maybe worth the extra money.
However if you are getting above 1800ma in 3-cell batteries, you have to run the numbers.
Paying for more than 35-C in these larger sizes may not be worth it.
A 2200ma 35-C Zippy battery is about 2.66 oz. heavier than your 1000ma 65-C Graphene.
But...if the math holds true, it will provide the equavilancy of 77-C in a 1000ma size battery.
If you want more pizzaz at these 1800ma and larger sizes...paying for higher C is not going to get the desired results that you see at the 1000ma size.
In these cases you need to go from "3-cell" 35-C 2200ma battery...to a "4-cell" 35-C 2200 battery.
But for smaller battery sizes in super-fast planes and quads...it's definately worth paying for higher C-ratings.
Nice job Nic. Your data proves that higher C rating equals lower internal resistance. Lower internal resistance means less voltage drop in the cell and more power to the motor. Generally speaking, the higher C rated batteries have heavier plates (conductors) and therefore lower IR (internal resistance). The difference in IR is small but power is current squared times resistance so there is 56 watts more power being dropped across the 35C pack than across the 65C. That's significant.
Very well done video! Thanks.
Mike
This subject is extremely important to me right now. I recently arranged some battery samples from a manufacturer & my calculations led me to order a battery with a relatively low C rating.
As it is a 6S battery with as low as 6000mAh but as high as 6500mAh, a 10C battery would comfortably deliver a peak of 60-65A to my motors. Collectively, my motors will only pull a max of 45A. That is close to 30% extra power.
My application is a slow flyer & any extra minutes would be precious. It's use would never include acrobatics or really anything fast.
From this thread I think it would be safe to assume that though a higher C value means more on-demand power, there would be diminishing returns in larger (or all) batteries due to more mass from thicker conductors that deliver that extra power.
Greater power doesn't mean greater efficiency.
Am I barking up the right tree?
megabotz
I think it would be safe to say that this thread is really dedicated to C rating of batteries in racing type multirotors.
For an example, let's take out the human element. Let's assume that the ship in question is being controlled by autopilot. All the same variables, just different batteries.
My position is that if you fly slowly (not racing) from point A to point B, the ship with the lighter battery (but same capacity) is going to fly further. If this isn't true, I missed the battery class entirely.
The conclusion I draw is that the higher C rating is proper if you need power in huge surges but if you are designing something that isn't meant to tear around corners at breakneck speeds, you are adding weight unnecessarily.
If you haven't guessed, I am not designing a racing quad.
megabotz