Leopard 6s vs 8s vs 12s

[DemonRC]

Well ole Strodedawg got me thinking about 12s so I'm up late chain smoking up and down the driveway thinking about it. On 3s 5000mah batteries in series I'm getting about 9 minutes runtime on my Leopard 1340kv. If you do the math on that to figure average wattage:


(60 min / 9 min) * 5000mah = 33333mah discharge / 1000 = 33.3A discharge average discharge rate


33.3A * 22.2V = 739.26 watts average usage


So I'll base the following scenarios on a 739.26 watt average usage. This isn't real world. I know each motor is going to perform differently, however, I need a realistic base number for comparisons sake.


Leopard 1340kv on 2x 3s 5000mah in series:


Total Volts: 22.2V


Total Capacity: 5A


Max RPM: 29748


Discharge: 739.26 watts / 22.2V = 33.3A


Runtime: (5A / 33.3A) * 60 = 9 minutes


Leopard 1340kv on 2x 6s 5000mah in parallel:


Total Volts: 22.2V


Total Capacity: 10A


Max RPM: 29748


Discharge: 739.26 watts / 22.2V = 33.3A


Runtime: (10A / 33.3A) * 60 = 18 minutes


Leopard 1000kv on 2x 4s 5000mah in series:


Total Volts: 29.6V


Total Capacity: 5A


Max RPM: 29,600


Discharge: 739.26 watts / 29.6V = 25A


Runtime: (5A / 25A) * 60 = 12 minutes


Leopard 700kv on 2x 6s 5000mah in series:


Total Volts: 44.4V


Total Capacity: 5A


Max RPM: 31080


Discharge: 739.26 watts / 44.5V = 16.61A


Runtime: (5A / 16.61A) * 60 = 18 minutes


I'm pretty sure I got it all right. If I missed something let me know and I'll fix it.

 

[grf]

looks good to me.

there is always a benefit to go higher voltage instead of more amperage (efficiency)

but apart from that all good.

 

[Obeast44]

there is always a benefit to go higher voltage instead of more amperage (efficiency)

In other words, much lower temps!!!

 

[strodedawg]

i wil be running 540 kv on 12 s

 

[DemonRC]

i wil be running 540 kv on 12 s

Wow 540kv eh? I'm not gonna even bother calculating it because the watt usage is not going to be anything near what I had on the 1340. It's going to much more efficient running. Anyways, that's still a theoretical 23976 RPM which should be plently fast depending on the pinion. I think you said something about a big pinion in another post. 16 tooth if I remember right? That should be a beast of a setup. Lemme know how that runs. I'm ready to drop the 1340 in my son's XBE and go with a lower kv setup also.

Oh, I forgot to ask, how do you like the Fightercat? I remember the pics of the programming interface looking rather amateur. Did they end up upgrading the software? Also, if you wouldn't mind, could you measure the fan size on the ESC?

 

[strodedawg]

just by doubling the voltage and halving the kv, speed should stay the same, but efficiency should go up

still waiting on the updated esc, that is wahat sparked the voltage increase

and i can't find the right kv motor for 16s that i like