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04222017, 01:06 PM
(This post was last modified: 04242017, 02:18 PM by devin.)
Ackmaniac, post:274, topic:15995, full:true Wrote:There is a little clip from the Simpson which fits to the situation here.
@Ackmaniac There is a little clip which fits to the situation here:
",0,0,http://www.electricskateboard.builders/t/understandingvescthedifferencebetweenbatteryampsandmotoramps/15995/275,20170201 16:52:06 UTC
Posts: 239
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04222017, 01:06 PM
(This post was last modified: 04242017, 02:21 PM by devin.)
Ackmaniac, post:274, topic:15995, full:true Wrote:There is a little clip from the Simpson which fits to the situation here.
@Ackmaniac so where's that proof that 10/150/160 batt/motor/absolute is harmful to VESC's??
@hexakopter
",0,0,http://www.electricskateboard.builders/t/understandingvescthedifferencebetweenbatteryampsandmotoramps/15995/276,20170201 17:02:36 UTC
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04222017, 01:07 PM
(This post was last modified: 04242017, 02:22 PM by devin.)
Ackmaniac, post:274, topic:15995, full:true Wrote:There is a little clip from the Simpson which fits to the situation here.
@Ackmaniac
@ 8 minutes 28 seconds in:
",0,0,http://www.electricskateboard.builders/t/understandingvescthedifferencebetweenbatteryampsandmotoramps/15995/277,20170202 00:39:10 UTC
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04222017, 01:07 PM
(This post was last modified: 04242017, 02:26 PM by devin.)
A question was brought up in the "Is my math right?!" thread relating to Understanding VESC: software.
This resulted in some new formulas which seem to enable prediction in advance of all or almost all "motor states."
The question was basically:
1440 W electrical @ %95 duty cycle = xxxx.xxrpm
It turns out you apparently can easily calculate the exact RPM for any W electrical and % duty cycle.
^ If you know any 2 of these values, it should be possible to calculate the 3rd value.
To perform these calculations, you only need 4 basic pieces of information about the motor:
 Pack V @ No Load RPM
 No Load RPM
 Ohm Winding Resistance
 Desired W Full Throttle
For example:
devin, post:75, topic:17037 Wrote:Desired Full Throttle Electrical W: 2000W
Pack V = 50V fixed constant
Ohm Resistance = 0.0415ohm
No Load RPM = 4500rpm
Batt Max Setting = 40.00A
Motor Max Setting = 219.52A
~0w electrical @ 100% duty = 4500.00 rpm
1000w electrical @ 100% duty = 4425.29 rpm
2000w electrical @ 100% duty = 4350.60 rpm
2000w electrical @ 95% duty = 4083.92 rpm
2000w electrical @ 50% duty = 1690.37 rpm
2000w electrical @ 43.12% duty = 1324.43 rpm
2000w electrical @ 18.22% duty = 0 rpm
In simple terms to predict all motor states you only need to know Pack V @ No Load RPM, No Load RPM, Ohm Winding Resistance & Desired W Full Throttle.
",0,0,http://www.electricskateboard.builders/t/understandingvescthedifferencebetweenbatteryampsandmotoramps/15995/278,20170204 16:06:50 UTC
