VEC 300 72V with 5000W QS Motor and 72V 85Ah battery - Configuration help needed

[Wildbeats]

Hello I need help about optimize parameters in my electric scooter the acceleration is very slow, anyone can help me?  I put parameters in photos. Thank you in advance

[Wildbeats]

More configuration photos

[Bikemad]

Hi Wildbeats andto the forum.

What is the maximum continuous (and peak) current that your battery can deliver under load? If this is insufficient, it would make a big difference to the available power during hard acceleration.

Do you have a voltmeter and/or ammeter to monitor what is happening under load? If the current draw is much lower than expected and the voltage drops considerably under load, this could be due to a weak battery or even battery cables that are too thin to handle the current load. If you measure the battery voltage at the controller terminals under load it will be noticeably lower than the voltage at the battery terminals if the battery cable thickness is insufficient.

Most of your settings appear to be OK, except that the maximum current @ 72V for the 12" 5000W QS motor appears to be 100A and the maximum continuous current is only 77A.

If the Average current (A) of 115 Amps refers to Battery Amps instead of Phase Amps, you might want to reduce this setting to 77 Amps. But if it refers to Phase Amps instead of Battery Amps, you may be able to increase it. 

The maximum unloaded motor speed I saw for that motor was 1320 rpm, but you have the Rated motor speed (rpm) set to 1230 rpm and the Max motor speed (rpm) set to 1400. 

Have you tried temporarily disabling the Flux-Weakening to how if affects the acceleration?

Enabling the Boost Function and setting it to Auto mode may improve your acceleration.

If you increase the Speed limit (%) does it affect the acceleration as well as the top speed, or just the top speed?

What version of the programming software are you using? There appear to be several new parameters that I haven't seen before for the VEC-300 controller, as well as some that are no longer available like Motor overtemperature protection.

I don't know what else to suggest.

Alan
 

[Wildbeats]

Hello!! Thank you for help, I Will test voltage when battery is low.

Motor is on 13 inches wheel do you recomend me change to 1320 rpm?

About average current (a) I don't know what to say all is new for me.

This changes you said to me can be put on Risk motor or battery about  Flux-Weakening and auto bost

About speed limit I have yo check.

Many thanks for your help

[Bikemad]

Motor is on 13 inches wheel do you recommend me change to 1320 rpm?

Unless your motor has a different maximum rpm to this one, you could set it to the correct 1320 value if you wish.

The maximum unloaded wheel speed with a 130/70 R13 tyre @ 1320rpm is approximately 127km/h (79mph).
The maximum unloaded wheel speed with a 130/70 R13 tyre @ 1230rpm is approximately 118km/h (73mph).

This changes you said to me can be put on Risk motor or battery about  Flux-Weakening and auto boost

Disabling the Flux weakening won't hurt the motor, and the Battery's BMS should protect the battery from excessive current draw if it is unable to deliver the set Boost current.
If you don't know the maximum peak discharge current for your particular battery, it might be better to leave the Boost function disabled.

Alan
 

[Wildbeats]

Motor is on 13 inches wheel do you recommend me change to 1320 rpm?

Unless your motor has a different maximum rpm to this one, you could set it to the correct 1320 value if you wish.

The maximum unloaded wheel speed with a 130/70 R13 tyre @ 1320rpm is approximately 127km/h (79mph).
The maximum unloaded wheel speed with a 130/70 R13 tyre @ 1230rpm is approximately 118km/h (73mph).

This changes you said to me can be put on Risk motor or battery about  Flux-Weakening and auto boost

Disabling the Flux weakening won't hurt the motor, and the Battery's BMS should protect the battery from excessive current draw if it is unable to deliver the set Boost current.
If you don't know the maximum peak discharge current for your particular battery, it might be better to leave the Boost function disabled.

Alan

This is my battery, many thanks for your help

[Wildbeats]

Just made changes that you advice me Max speed un GPS 92km/h and aceleration 0-80km/h 10,5 seconds I don't understand, nothing change

[Bikemad]

I couldn't find any maximum current figures for that battery but with 20 sets of 36 paralleled 18650 cells it should be capable of 170A continuous if good quality "2C" cells and a high current BMS have been used.

Just made changes that you advice me Max speed un GPS 92km/h and acceleration 0-80km/h 10,5 seconds I don't understand, nothing change

I didn't say it "would" improve, I only said it "may" improve:

Enabling the Boost Function and setting it to Auto mode may improve your acceleration.

Unfortunately, you have now confirmed that it hasn't improved, but if you hadn't tried you would not have found this out. 

Your initial post said that "the acceleration is very slow", but that was a bit misleading, as I don't consider 0-80km/h in 10.5 seconds as being too unreasonable for 6.5kW of power.
(100A@72V would draw 7.2kW of power from the battery, which would produce approx 6.5kW of power at the wheel @ 90% efficiency.)

As a comparison, the Vectrix VX-1 Scooter has a maximum power output of 35kW peak and has a 0-80km/h time of 6 seconds and the Harley-Davidson LiveWire has a maximum power output of 78 kW and a 0-97 km/h time of around 3 to 3.5 seconds.

The Vectrix's acceleration is approximately 50% slower than the Harley-Davidson, but it has less than 50% of the Harley-Davidson's power.
Your scooter is only 4.5 seconds (43%) slower from 0-80km/h than the Vectrix and is using just 18.57% of the Vectrix's power to achieve it.

If you want quicker acceleration you will need more power, which would mean overloading the 5000W motor by using a higher current motor controller, or using a higher powered motor and a higher powered controller, assuming your battery would still be capable of supplying the required power.

Acceleration is the result of Force divided by the Mass. If you doubled the available Force by doubling the power output of the motor, you would effectively double your acceleration and halve your 0-80km/h time.

If you could produce 13kW of power at the wheel without any extra weight increase, your 0-80km/h time should decrease from 10.5 seconds to just 5.25 seconds if all of the additional force can be applied directly to the road through the tyre.

Therefore, assuming 100% grip was available between the driven tyre and the road surface, a power output of 22.75kW should theoretically produce a 0-80km/h time of around 3 seconds on your scooter, making its acceleration directly comparable to that of the Harley-Davidson Livewire.

Alan
 

[Wildbeats]

I couldn't find any maximum current figures for that battery but with 20 sets of 36 paralleled 18650 cells it should be capable of 170A continuous if good quality "2C" cells and a high current BMS have been used.

Just made changes that you advice me Max speed un GPS 92km/h and acceleration 0-80km/h 10,5 seconds I don't understand, nothing change

I didn't say it "would" improve, I only said it "may" improve:

Enabling the Boost Function and setting it to Auto mode may improve your acceleration.

Unfortunately, you have now confirmed that it hasn't improved, but if you hadn't tried you would not have found this out. 

Your initial post said that "the acceleration is very slow", but that was a bit misleading, as I don't consider 0-80km/h in 10.5 seconds as being too unreasonable for 6.5kW of power.
(100A@72V would draw 7.2kW of power from the battery, which would produce approx 6.5kW of power at the wheel @ 90% efficiency.)

As a comparison, the Vectrix VX-1 Scooter has a maximum power output of 35kW peak and has a 0-80km/h time of 6 seconds and the Harley-Davidson LiveWire has a maximum power output of 78 kW and a 0-97 km/h time of around 3 to 3.5 seconds.

The Vectrix's acceleration is approximately 50% slower than the Harley-Davidson, but it has less than 50% of the Harley-Davidson's power.
Your scooter is only 4.5 seconds (43%) slower from 0-80km/h than the Vectrix and is using just 18.57% of the Vectrix's power to achieve it.

If you want quicker acceleration you will need more power, which would mean overloading the 5000W motor by using a higher current motor controller, or using a higher powered motor and a higher powered controller, assuming your battery would still be capable of supplying the required power.

Acceleration is the result of Force divided by the Mass. If you doubled the available Force by doubling the power output of the motor, you would effectively double your acceleration and halve your 0-80km/h time.

If you could produce 13kW of power at the wheel without any extra weight increase, your 0-80km/h time should decrease from 10.5 seconds to just 5.25 seconds if all of the additional force can be applied directly to the road through the tyre.

Therefore, assuming 100% grip was available between the driven tyre and the road surface, a power output of 22.75kW should theoretically produce a 0-80km/h time of around 3 seconds on your scooter, making its acceleration directly comparable to that of the Harley-Davidson Livewire.

Alan

This is my scooter, manufacture offer 2 versions with the same battery and same motor but with more aceleration, I think are differents parameters, this is because I think accelaration have to be faster.

http://en.jonway.com/E_Bike/MJSE.html

About this "Enabling the Boost Function and setting it to Auto mode may improve your acceleration", I did not do modifications because I´m not sure if put risk controller, motor or battery.

Many thanks your help, you are very kind with all information you give me.

[Bikemad]

(Peak Power:18720W) 6-8 seconds can reach speed 100km/h

To achieve that amount of output power would require 289 Amps of battery current @ 90% efficiency.

The VEC-300 controller is only rated for 100 Amps @ 72V which is nowhere near the amount you would require.

However, it would appear that the motor is obviously capable of producing a lot more power provided that your battery can supply, therefore you should be able to enable the Boost function and see if it makes a difference.

If it does make a difference, you could also try increasing the boost current level by 10 Amps each time and see if the battery is still able to supply this additional current without the BMS cutting the power.

The boost current is only available for short periods at a time, but it will hopefully be able to increase your acceleration when you need it most. 

Alan
 

[Wildbeats]

(Peak Power:18720W) 6-8 seconds can reach speed 100km/h

To achieve that amount of output power would require 289 Amps of battery current @ 90% efficiency.

The VEC-300 controller is only rated for 100 Amps @ 72V which is nowhere near the amount you would require.

However, it would appear that the motor is obviously capable of producing a lot more power provided that your battery can supply it, therefore you should be able to enable the Boost function and see if it makes a difference.

If it does maker a difference, you could also try increasing the boost current level by 10 Amps each time and see if the battery is still able to supply this additional current without the BMS cutting the power.

The boost current is only available for short periods at a time, but it will hopefully be able to increase your acceleration when you need it most. 

Alan

Perfect I will try later in the afternoon here in Spain I will see whats happends. Put 200a in boost current it ok or I start with less? Many thanks.

[Bikemad]

Put 200a in boost current it ok or I start with less? Many thanks.

Sorry, I missed this part yesterday while quickly reading through my emails.

The controller should not accept values to be entered that are outside its permitted range, so it shouldn't be a problem for either the controller or the motor.

However, if you find that your battery's BMS cuts out during the short period of the 200A load you will have to reduce the boost current setting.

Alan
 

[Wildbeats]

In another forum said me this:

I would disable the Flux weakening until after you get everything tuned the way you want and still want more top speed. I would disable the 3 gears function until you get acceleration the way you way. Also disable the speed limit as well as set it to 100% along with all speed ratio settings. (DONE BECAUSE YOU SAID TO ME, ABOUT 3 GEARS FUNTION NOTHING DONE)

The glaring thing to me is the low start up current of only 30A. If increasing it begins to make starts too hard and jerky from a stop, then enable the boost current setting, but don't start so high as 200A at first. (YOU SAID ME ABOUT BOOST, BUT NOTHING DONE I WANT TO BE SECURE ABOUT CORRECT VALUES)

Before increasing the phase and average current limit settings try to find out what the manufacturer recommends. If that is not possible do only the items above first, and if you still want more acceleration begin to gradually increase those settings (YOU SAID ME)

As you start to get more performance, then you need to start monitoring motor and controller temperatures after riding as hard as possible to help you understand your system's limits. If precise temperature measurement isn't possible, even using your hand to feel for warmth of both when stopped can be very useful info in tuning your system higher (I don´t know it this is secure hehe)

Keep in mind that the hardest thing on your system (which shows up as heat) is repetitive hard launches and going slowly under heavy load (like up steep hills).

[Wildbeats]

Put 200a in boost current it ok or I start with less? Many thanks.

Sorry, I missed this part yesterday while quickly reading through my emails.

The controller should not accept values to be entered that are outside its permitted range, so it shouldn't be a problem for either the controller or the motor.

However, if you find that your battery's BMS cuts out during the short period of the 200A load you will have to reduce the boost current setting.

Alan

Do you think bms will cut? I don't want to break the battery, I don't know about bms. Many thanks.

[Bikemad]

Without knowing what the maximum current rating of the battery's BMS is, it's impossible to say whether it will cut out or not.

If your battery is supposed to provide 14400W (or 18720W) peak power to your scooter, it should not cut out under a 200A load.

The BMS is designed to protect the battery by cutting the power being delivered if its maximum current limit is exceeded, and when this happens, it should either reset automatically when the load is removed, or reset manually by turning off the power and turning it back on again.

Alan