I have tested running 6s and 12s on 230kv motors. I get much more torque,acceleration and speed with 12s on those motors. And twice the battery range at 12s for a given amp hour rating. i.e.: 6s/5000 or 12s/5000 I’m sorry but saying that voltage is converted into amperage does not make sense. voltage is electrical pressure amperage is electrical flow https://learn.sparkfun.com/tutorials/voltage-current-resistance-and-ohms-law
Yea I remember those tests. More speed on 12s for sure but inside a motor all that the motor uses to make torque is amps and the esc is converting the voltage to amps. Volts in the battery are converted by the vesc to amps Vedder:
What causes heat in both the motor and VESC is the motor current. Neither the motor nor the VESC care about the battery current, only the battery does. Also, the battery current can never be higher than the motor current. So when you set the current limits you should set the motor current to a suitable value for the motor and VESC. For setting the battery current you only have to look at the battery. Most batteries, especially LiPos can provide more discharge current than you need, but the charge current is somewhat limited. 18650 cells might not be able to provide as much current as the motor can take, and if the battery has a BMS (such as the space cell) this can also limit the discharge current. Note that the battery current is directly proportional to the motor current times the speed (actually modulation). On low speed the motor current is much higher than the battery current, and on full speed they are the same. This means that if you have very high top speed the VESC will get warm on low power levels when running on low speed. The faster you go, the less heat the VESC generates per power output because the motor current is what causes heat and the battery current is what defines power.
Regarding the motor getting hot under a given load, this has nothing to do with the kv, as I wrote a bit about here: http://vedder.se/2014/10/chosing-the-ri … kateboard/ so if you have a given motor with different kv choises and the same copper fill, all of them will generate exactly the same amount of heat going up a given hill at a given speed. Changing to a higher kv value and running on lower voltage and higher current does not change the heat generation of the motor one bit. The motor only cares about the torque it has to provide, regardless of the kv/current combination."
Volts x amps is power but maybe that power isn’t realized until u hit a high speed from the voltage, otherwise u should be able to push enough amps even with a low voltage to get the same performance
The quote above isn’t very relevant and I remember ur results and I’m trying to make them fit this info about a motor being able to perform just as well on any voltage. In ur tests u were at max speed I think on 6s and half on 12s right? It should end up a lower amp draw from the battery on 12s but the same amp draw for a given torque regardless of the voltage. Why those amps are many be easier to push through could be simply ohm’s law. I’m not sure it even happens though. How’s 5 to 15 mph speed on either?
If you put a clamp amp meter on the 3 phase wire and work the throttle up and down as I did. You will see that the Esc regulates the voltage to the motor and that the amperage stays constantly regardless of how much throttle you apply. The amperage only increases as load is applied to the motor. I proved this theory by testing it myself. As far as the statement " voltage is converted to amperage" it makes no sense. And it doesn’t agree with basic electrical theory. Volts is the measurement of electrical charge. Amps is the measurement of electrical current which is the flow of current through a circuit. You can’t turn one into the other.
The vesc has two limits the amps from the battery and the amps to the motor. On 12s with a given load let’s say it’s 10 amp draw from the battery and 15 to the motor and on 6s it can be 12 from the motor and still 15 to the motor.
The vesc turns voltage into amps from what I read. That’s doable. Maybe more amps can be pushed with the higher voltage but I read either system can perform the same if the kvs are adjusted
I could not find where Vedder said that “the Vesc turns volts into amps” I think your misunderstanding what he’s saying. You can’t turn volts into amps. again: volts and amps are 2 different measurements of 2 different and distinct characteristics of electricity. You can’t turn one into the other. You should read up a little on electrical theory then you will see what I mean.
Volts are turned to amps and vise versa often with power coming into houses converting with a transformer.
When u did ur test where u stayed at the same kv and doubled the voltage u kept to the same speed and load I think I remember. How was acceleration up to speed on either voltage? My one question about the difference between running 12s vs 6s is if the amps are able to be pushed faster with the higher voltage and increase acceleration. I read it’s not the case and of it is it likey would be the battery amp limit…which will be more easily reached on 6s vs 12s…as more amps are drawn from the battery on that system. On the 12s…voltage is converted to amps and there will be less amps drawn from the battery
Volts are not turned into amps or visa versa with power coming into houses with a transformer. A transformer is an electrical device that takes electricity of one voltage and changes it into another voltage.
It changes the ratio of amps to volts.
A transformer is an electrical device that takes electricity of one voltage and changes it into another voltage. http://energyquest.ca.gov/how_it_works/transformer.html
BTW, Amps are not “pushed”. They are pulled by the motor. And, as the load is increased, the amps are increased as well.
Transformers don’t increase current. They change voltage. Thats all they do. Load increases current
It gets complicated and I think this link explains well:
But a motor isn’t a transformer anyway. My point of talking about any of this is to find out how 12s vs 6s perform. Assuming, which I do, and hopefully you do, that a motor is just as efficient at producing torque using any voltage(with a kv change)…you can get just as much power out of it. But maybe with motor voltage you can push more amps over a given resistance and that would account for quicker acceleration. But I don’t even know what your test results showed…did u get faster acceleration with the higher voltage? Do people get faster acceleration with higher voltage? And if so why?
um your wrong
with a transformer you can make more amps
how do you think electricity is transported? they use a step up transformer to turn 120V at say 100 amps to 1200V at 10 amps and then a step down to turn it back in to 120V at 100 amps. you can get more amps at a loss of voltage and can get more volts at a loss of amps.
~source Canadian forces poet course unit 3 alternating current~ and http://www.explainthatstuff.com/transformers.html
P=IE power = current x voltage
power in watts current in amps voltage in volts 1000 watt light bulb 1000 watts\115volts=8.7amps 1000 watts\220volts=4.5amps The light bulb is the Load. it takes 1000 watts of power to handle the load. Think of your motor as a variable Load. as the load increases, more power is needed to handle the load. more power requires more voltage or more amps. P=IE Since you control the amount of voltage to the motor via the Esc. the current(amps) becomes the variable. This is how going uphill at half throttle could cause higher amp flow that going uphill at full throttle. More throttle more voltage and less amps.
I do get much faster acceleration with higher voltage. 12s vs 6s
Then what would be the point of a transformer? Ur giving me equations we know but omitting them in ur transformer deductions. We run high voltage with low amperage and then step it down and it converts back to cumbersome amps
But ur motor test. Could u do one where u test acceleration
Ok. Why? Or I should say why do you think? I don’t know what I think
I have tested acceleration. road test with 12s and 6s