10S4P vs 8S5P,.. both 40 cells

[randyc1]

This will be for a E skate single motor 6364.

Is there a difference between a 10S-4P.. and a 8S-5P,... both 40cells,...did the calculations and seems the same ?


Let's assume I use 2000w going up a hill :

10s4p,...2000w/37v =54A,.../4p =13.5A per cell

8s5p,....2000x/29.6 =67.5A,../5p =13.5A per cell

So Amps per cell is the same ?


I know (8S 5P) will lower my RPM (29.6x245kv) & top speed to 26mph,... but do i GAIN anything with 8S4P ?

I get enough speed with 8S , ..but 10S is suppossed to be better for VESC ???


Thank you.

 

[Wheazel]

Why are you assuming that the skateboard will pull less amps at 10s compared to 8s?
Do you have a powerlimiter that will be set at 2kW?
If you get the required speed at 8s I see no reason to go 10s and get less Ah in the pack.

I dont know what VESC means, are you refering to the voltage for the esc?

 

[randyc1]

Why are you assuming that the skateboard will pull less amps at 10s compared to 8s?
Do you have a powerlimiter that will be set at 2kW?
If you get the required speed at 8s I see no reason to go 10s and get less Ah in the pack.

I dont know what VESC means, are you refering to the voltage for the esc?

VESC is Vedder's (guy who invented it) Electronic Speed Controler

As an e ample if i needed 2000w of power , yes 10S does pull less Amps than 8S , W = V x A

 

[randyc1]

https://endless-sphere.com/forums/viewtopic.php?f=35&t=75572

Yes that is my post , just thought it would be more appropriate here in Battery tech.

Have you ever seen Vedder's post on how to choose Motor , kv, ESC ?

 

[Wheazel]

Why are you assuming that the skateboard will pull less amps at 10s compared to 8s?
Do you have a powerlimiter that will be set at 2kW?
If you get the required speed at 8s I see no reason to go 10s and get less Ah in the pack.

I dont know what VESC means, are you refering to the voltage for the esc?

VESC is Vedder's (guy who invented it) Electronic Speed Controler

As an e ample if i needed 2000w of power , yes 10S does pull less Amps than 8S , W = V x A

Well ofcourse the U*I=P holds true, and I think you are missing my point.
Do you have any means of regulating the power?
If not, I am confident you will pull more power with the 10s setup on average. The 2000W scenario is theoretical.
Therein lies my point, it would be easier to be efficient with 8s. Especially if 8s means a suitable topspeed.
If you do have a CA for example, 10s would be comparable(probably at a slight advantage) to 8s if you changed gearing to get the same topspeed.

These are my thoughts without any specific knowledge about the Vedder esc.

 

[okashira]

Randy, you are correct in your assumption that more S will be less current. Especially as the VESC can do FOC now.
So use the highest voltage you can that wont kill the controller. It will be more efficient at higher voltages.

 

[randyc1]

Randy, you are correct in your assumption that more S will be less current. Especially as the VESC can do FOC now.
So use the highest voltage you can that wont kill the controller. It will be more efficient at higher voltages.

OK 10S4P it will be!

Thanks!

 

[999zip999]

I like voltage.