Hydra with Archon in Grin motor simulator

[jharrell]

In hopes of trying to get a better understanding of how big a battery I would be happy with on a Hydra and just have a better understanding of its performance with different wattages and gear ratios I attempted to simulate a Bafang G510 with Archon controller on Grins motor simulator.

From what I know the G510 is a 4 pole pair motor with 55Kv and 18:1 internal gear ratio. While the Grin simulator says it supports entering raw pole and Kv along with a gear ratio I was getting odd results, however if entered similar to the built in mid drives as 1:1 gear ratio then doing 72 effective poles with 3.05Kv the results make sense (4*18=72, 55/18=3.05).

I had to make some assumptions due to lack of info, for instance I lowered the controller resistance to .01 to account for the Archon efficiency and made the 1000w controller 30 amps while 2300w is 57 amps and most of the motor parameters are based on the BBSHD provided by Grin except for poles and Kv.

System A is a stock Hydra with 1000w option
System B is a Hydra with 2300w options and 52 tooth front chainring to try and maximize top speed.

Notes:
1. Drag significantly changes tops speeds, i.e. MTB Upright vs Tuck, so pay attention to that, also weight.
2. Battery is 52v and simulated at that, while a full 52v battery will be 58.8v and have higher top speed and power output.
3. Throttle set to auto lets you slide speed on chart and see wh/mi at that speed. It is simulating about 13.4 wh/mi at 20mph which is 64 mi range with 16ah (~800wh) battery, which would be great for me but not sure how accurate the efficiency is here again lots of assumptions, need more accurate parameters.

Any corrections or input welcome:

WW Hydra Grin Motor Simulator V1

 

[jharrell]

One other thing to note based on the simulator is the 1000w and 2300w are nearly identical in efficiency / range at the same constant speed, which make sense as it take the same power to go the same speed and the motors are identical except for software. So unless there is some other factor not being simulated you should not be sacrificing range by going to more powerful version of the motor assuming the same constant speed.

Things get more complicated with climbing and start / stop as the 2300w can accelerate and climb more much quickly by using more power which would reduce range over the less powerful version. This is where I would hope I can program the 2300w to have lower assist levels that match the 1000w version when the extra power is not needed.

 

[Acme]

It’s my understanding that you can set your echo modes to be the equivalent of a 1000 W motor and get exactly the same efficiency as if you had total 1000 W motor that would only draw that much in the turbo mode.

 

[jharrell]

It’s my understanding that you can set your echo modes to be the equivalent of a 1000 W motor and get exactly the same efficiency as if you had total 1000 W motor that would only draw that much in the turbo mode.

Yes this is exactly what I would want to do, utilize as a 1000w motor much of the time, but have the full 2300w on tap as needed.

 

[Jayaznpride]

One other thing to note based on the simulator is the 1000w and 2300w are nearly identical in efficiency / range at the same constant speed, which make sense as it take the same power to go the same speed and the motors are identical except for software. So unless there is some other factor not being simulated you should not be sacrificing range by going to more powerful version of the motor assuming constant speed.

Things get more complicated with climbing and start / sto as the 2300w can accelerate and climb more much quickly by using more power which would reduce range over the less powerful version. This is where I would hope I can program the 2300w to have lower assist levels that match the 1000w version when the extra power is not needed.

Im new to the ebike world with my Hydra 2300w. Pushkar mentioned on his YouTube tutorial that you could change the torque sensitivity where if left on zero it would rely more on the torque sensor and on 10 if would rely purely on cadence sensor. Playing around with the bike with constant speed as long I didn't go up hill or change to a higher gear I could maintain my speed without the motor assisting as much on 0 torque sensitivity vs 10 torque sensitivity.

 

[onlineaddy]

...change the torque sensitivity where if left on zero it would rely more on the torque sensor and on 10 if would rely purely on cadence sensor...

I think you have that reversed: low (0) torque sensitivity would mean it's relying on cadence, and vice versa.

 

[Jayaznpride]

I think you have that reversed: low (0) torque sensitivity would mean it's relying on cadence, and vice versa.

Not according to Pushkar tutorial. From my expirence riding with the bike and checking the settings 0 is more torque sensor

 

[onlineaddy]

Not according to Pushkar tutorial. From my expirence riding with the bike and checking the settings 0 is more torque sensor

I see that, though you do see where I'm coming from, right? I'll have to keep this in mind when I'm making any changes to the programming. Thanks for bringing this up.

 

[scrambler]

Im new to the ebike world with my Hydra 2300w. Pushkar mentioned on his YouTube tutorial that you could change the torque sensitivity where if left on zero it would rely more on the torque sensor and on 10 if would rely purely on cadence sensor. Playing around with the bike with constant speed as long I didn't go up hill or change to a higher gear I could maintain my speed without the motor assisting as much on 0 torque sensitivity vs 10 torque sensitivity.

Constant speed on flat ground, is the one condition where having the PAS set to use more the Cadence sensor than the torque sensor is better.
The reason is as follow:
PAS on torque sensing provide power proportionally to the pressure you put on pedals. This is ideal in changing environment like on trails where you want immediate change of power at the tip of your feet.
But when you are on flat ground going at constant speed, your tend to relax the pressure, and your pressure on the pedal become less uniform, with time of low pressure and time of higher pressure to regain speed. When using primarily torque sensing, it can feel uneven and less than you need.
On the opposite, the Cadence sensor delivers a constant power output based on the chosen level.
Off road that is not great as you have to constantly adjust the PAS level to the changing needs of the terrain. But on flat ground at constant speed, at the appropriate level it will maintain the power assist better.

This is why you may want to have different modes setup for these various situations.

Need quick delivery and frequent modulation of the power at the tip of your feet, weight the setting towards Torque sensing.
Need regular delivery of power without the need to change that power level often, weight the settings more towards Cadence sensing.

 

[jharrell]

My current Juiced RCS feels fine with a the torque sensor always on even a constant speed, it can be turned off in the menu but not worth it. It does feel better a certain constant speeds with certain assist levels, for instance 3 out of 5 is better for 20mph cruising while 5 is too jumpy, slight pedal pressure wanting it to go faster, but at 25mph+ level 5 is perfect. I am not sure how its programmed internally as thats not publicly available, but the torque sensor is definitely on all the time although it may become less sensitive based on assist level and speed.

I am interested to know how an Archon responds but all accounts say it's up there with the Euro motors in smoothness.

 

[scrambler]

Juiced uses both Torque and cadence sensor, so they most likely have taken care of what I described above by blending them appropriately.
You never want only one, but the appropriate blend. What I was describing is one aspect of the blending requirement based on the type of usage situation

 

[jharrell]

If anyone has real world data from their Hydras please share, I can then use that to try and make the simulation parameters more accurate. The main thing is trying to get a grip on wh/mi at specific speeds. Does the stock Bafang display track any of that? My Juiced display tracks wh/mi and total watt hours and amp hours.