PINNED - R-Net for dummies

[Burgerman]

While actually rolling? Or stalled. It wont load it will give an error. Tried before by accidentally uploading the 120A settings to a 90A power module.

[emilevirus]

Going uphills. ~100ish.

[Burgerman]

Lets see a screenshot of that. Because mathematically it makes no sense at that mOhms according to ohms law. You would need to be super slow and steep ramp.

[emilevirus]

Here: https://share.emilej.com/RNet_Programme ... sJzsPN.mp4
While going uphills with BMS monitoring: https://share.emilej.com/Screenrecordin ... 172516.mp4

[Burgerman]

The BMS link shows up to 90A, across 2 motors. Thats 45A max per motor at the battery at a 100% pulsewidth. Thats what I expected.
If that was configured correctly with low impedance motors you would see a peak of 220 battery amps at approx 13rd to 1/2 max speed as you accelerate up a slope.

The R-net link shows a stalled motor so at that super slow or stationary speed because its all at low or zero voltages. it can pull 100A plus at super slow speeds, even a 2 pole can. Try that while rolling. You can see that you were not moving much by motor voltages. Even then, it spiked at a max of 117A once on one motor. So setting anything to 130 wont make any difference. It wont use it.

[emilevirus]

Are you sure? I don't think R-Net allows much more than 120A pulled from the battery. I was stalled the other day and max I saw being pulled from the battery was ~130A. Same thing when I had my Magic Extreme X8. It peaked at around 130A stalled and that's 4x motors ~30mohms resistance.

[Burgerman]

With a low impedance motor that is stalled, with maximum pulsewidth ALLOWED by the controller that limits it firmly to 120A per motor, it can absolutely pull 100% of that 120A per channel per motor. Unless HEAT, stall protection programming, or rollback timer, and a combination of those kicks in. Which it does pretty fast. But we will ignore that for now as my chair can hit 240A battery for an instant now and again.

THIS IS IMPORTANT!!!
You dont understand yet how motor current and battery current are totally different things. I am trying to explain WHY and how that works. And show why motor impedance is everything here!

With a typical good 30mOhm ish 8mph motor impedance (plus battery and motor and controller inpedance) with a motor that IS NOT rotating, (stalled) @ 120A each (x2) this may well occur at SIX motor Volts. (6V). Thats a total of 240A @ 6V.
This means that the motors draw 1440 Watts from the controller. Do you understand that? Because 6V (pulsewidth limited to 120A by 25% PW) x 240A is 1440 watts.

So again for easy numbers at the battery, 1440W div by the battery voltage = battery current. So the draw at the battery is just 60A while at the motor it may be 120A each. Why? Because 60A x 24V = 1440W. We are ingnoring many losses etc to make it easy to understand.

Please read that several times or ask me questions if you dont get it! Its very important.

Now...
Lets say you are now at HALF speed. Say 4mph. Now that motor is GENERATING half the battery voltage as it spins. So to pull 120A it will require that 6V over and above its motor generator voltage. So now we have to supply it with 12gen+6V (18V) to maintain full 120A performance up a hill loaded to the max. Thats a pulsewidth of 75%. That means the battery current is now risen to 3/4 of the motor current. Or lets do the watts. 18V X 240A motor is now = 4320 watts. So battery current has risen to 180A. If you went a little faster while still at max acceleration, the pulsewidth eventually hits 100% so 240 battery amps.
(The reason YOU dont see that is because your motors are higher impedance. See next!)

Now lets say the motor impedance is 4x that. And so its 120mOhm for easy numbers. Now it can still pull the same 120A at stall. JUST. But it needs 4x the voltage (pulsewidth) to do so. So not 6V but now 24. And now battery current is = to motor current at stall...
And then the following happens. As you start to roll, the motor generates a voltage. So now we have to add MORE than 24V to the motor in order to pull 120A. And we cant... So as the chair speeds up at max acceleration up a hill, the current drops away from the peak 120A per motor at stall, to zero at maximum unloaded speed. Once above stall speeds, compensation, or bigger amp controllers cannot do anything. It means that at faster speeds, compesation does nothing. At full speed these motors pull very low currents. And so the chair slows a lot on hills etc.

These are 2 example of why motor impedance affects torque, battery range, as you speed up. They are extreme examples with simplified numbers to make it clear.

[Burgerman]

I was stalled the other day and max I saw being pulled from the battery was ~130A. Same thing when I had my Magic Extreme X8. It peaked at around 130A stalled and that's 4x motors ~30mohms resistance

Thats for several different reasons.
In the controller and in the wiring there is greater internal resistance than in the motors themselves, especially so with 4 motors as a proportion of the total.
Then, you NEED motor load compensation to be correctly configured too before you will see anywhere near max 120A at the motors.
Then theres a fairly rapid mix of temp, stall protection, and limited time at high power all running at once limiting what it can do.

But the BIGGEST reason is by far because the LOWER the motor impedance is, then the lower the battery current is even while stalled at 120A per motor. As explained in the above post. If you do not understand the relationship between motor current and battery current and why its a sliding scale with speed, and with motor impedance then you will never unerstand any of this.

************************
2 high impedance weak motors, draw much MORE battery current than 2 low impedance high torque motors. At the very same 120A motor current.
************************

[emilevirus]

I understand that but I mean. I always struggle to get over my doorstep. It stalls even my 10kph chair then pulls 130A from battery. If I hold my joytick it holds steady at 130A. Does the controller limit me or the motor resistance does? If I plugged the motors directly on the battery allowing unlimited current, would it go over or still stall?

[Burgerman]

Depending on impedance a direct battery connection would instantly strip the gears and destroy the motor or it would pull less than 120A and do no better than if connected to the controller. It would also try and instantly flip upside down.

Variables.
Battery impedance.
Motor impedance.
Gearing.
Battery and motor loom impedance.
Controller impedance.
Controller roolback/antistall/current boost timer, normal current timer, temperature current level/slope
Weight.
How motor load compensation is configured.
Actual acceleration setting for turn and forward power also determine if compensation ramps up faster than the controller rolls back power and a high impedance motor needs to ramp up much further. So takes longer.

Do you understand what determines BATTERY current?

[Burgerman]

I understand that but I mean.

I dont think you do.

I always struggle to get over my doorstep. It stalls even my 10kph chair then pulls 130A from battery.

How much it pulls from the BATTERY tells us practically nothing useful at that point. Nothing.
What is the MOTOR CURRENT?
1. If its 120A then your gearing is too tall for the motor.
2. if its not 120A then find out why. Could be motor impedance, compensation or forward acceleration speed settings, rollback, temp, ani stall settings, timer settings, battery or cable resistance, etc too.

If I hold my joytick it holds steady at 130A. Does the controller limit me or the motor resistance does?

MANY things do, some are described in the previous posts that you have not read properly!!!

[emilevirus]

I just tested and yes it hits the 120A limit. That's my whole point. Increasing the limit would help in that case...

[LROBBINS]

Here' from the Roboteq user's manual, is another way of saying what John has already explained. Do note the equation at the bottom.

[Burgerman]

And note 1. above as well...

Only at stall. The moment you roll it will drop anyway.

At 120mOhm it will - just about reach 120A with compensation working really hard, but only at stall. And not for long. As you roll then it will reduce current and compensation cant help any longer.

At 30mOhm it will be able to maintain this level of torque right up to above half speed. And draw less battery current so much more efficient.

Setting to 130A in the power module will be highly unlikely to work. I cant even choose it on any of the OEM software I have here it wont allow it. I also doubt that it will allow you to send that figure to the controller. If it does then it will likely ignore it. Even if it allows it and it works, it will just roll back power faster... Unless you fit a fan too and hope the stall protection roll back doesent kick in faster.

The real answer is as I have said all along.

70 to 100A controllers for 4 to 6 mph (6kph) chairs.
100 amp controllers to 120A for 6 to 6.5 (10kph) chairs.
Nothing works properly on 8mph (13kph) chairs and I have tried a lot of options... Unless you are light, dont expect a lot.

The very reason I started messing about with the roboteq is because a) its got half the impedance and 150A solid per channel. So it would give sensible torque on 8mph motors. Adding extra battery voltage does NOT change torque. But it does allow it to maintain that high torque to much higher speeds.
Remember that Amps = Torque in direct proportion /roadspeed. (gearing).

So double the speed? Same voltage? you need 2x gearing. And 2x the torque at the motor... So double the Amps.

[snaker]

I am trying to edit a r-net data file by r-net OEM software (downloaded from dietz website). When I change the motor output voltage to 29V, I get an error message. It says max allowed voltage is 25V. I saw somebody here already changed this parameter to a value higher than 25V. So is that because I am using a wrong software? Or must I have an OEM dongle? Or do I need change some other parameters first before I am able to increase the motor output voltage to 29V?

I note that I only edit the r-net data file without writing it to the PM. I am able to change the motor output voltage to any value less than 25V.

[Burgerman]

I never saw any module or any software that allows that. And yes I saw that on here too. But you probably wouldnt want to anyway. As under load, and especially when discharged a bit, even with lithium the voltage drops significantly. This is designed to allow some headroom for full safe control. 25 is already too high even with lithium.

[snaker]

I intend to use a 9s lifepo4 pack.

[emilevirus]

The magic Extreme allows it. Use Sunrise OEM software. Load it onto your PM then check if it's back to 22v. If not, you're good.

[Burgerman]

I have here 2 versions that are R-Net GENERIC version 7.0.xxx from two sources inc PG Drives that are both supposed to be the latest.

One is compiled to work with the newer PM2 and has all sorts of battery config options and all sorts of internet connections and spying uploading motor and battery usage parameters and that keeps massive logs...

On the face of it they look the same.

On the options on the left there are a few differences lower down and in the menus.

Take a careful look!
They dont install over the top of each other - both work at at once and are both GENERIC V7.0 in the start menu.

[Burgerman]

And note here.
Many battery values can be set (yellow = the ones I changed) that are not normally available.
Also note that a boost current above 120 not allowed. And a motor voltage above x voltage (varies with module firmware/preset) cannot be set above 25 in this case.

The actual max values here depend on the PM firmware and its existing preset that you will be modifying. I just tried setting a PM90 to 120 boost. It refused to "stick" on one. And it refused to load at all with an error on another.

So the answer to all these questions about what feilds appear, which are valid, and what can actually be changed, and what could be adjusted but isnt visible is highly confusing! Even the version of the software (and the brand if not Generic) changes all this.

The SAFEST options are to use the preset from your own power module with the brand of chair and programmer that match. But that sometimes loses out on a few important options. And then its best to add those as seperate SUBSET files, then redownload your programing preset all over.
Say button mapping. Or motor voltage adjustments. Or battery configuration settings.

[emilevirus]

Generic version won't allow past 25v, Sunrise does.

[emilevirus]

I wonder. Can the new battery options be flashed on the older PMs?

[Burgerman]

Well if not it wont let you do it, or it gets ignored. Try it, as a rnss file cant do that here as stuck on bed.

[Burgerman]

Well if not it wont let you do it, or it gets ignored. Try it, as a rnss file cant do that here as stuck on bed.

Sunrise version lets you CHOOSE 16 to 50 Volts. For max motor voltage. And you still get an error if any motor noise or regen spikes hit 35V even for a ms.
It cant be loaded on all controllers though not even all sunrise ones. Some give error. Some ignore it. And obviously you cant get more than the loaded motor voltage anyway. And it takes away the headroom needed to have linear control. Especially noticible as almost no steering available when going up a hill.

[emilevirus]

Where can I find that PM2 software? I don't think you uploaded it did you?
Worse that can happen is a cap pops while in public, everyone thinks it's a gunshot and they call the police on you.

[Burgerman]

That and a couple of mosfets go with it...
What actually happens is that it doesent go any faster under power but steers crap. But going DOWNHILL it speeds up more at full stick - at least on lead as it can push the voltage higher (bcos impedance) and you risk those pops you mention... Its not the average voltage thats the issue. But the noise in the regen signal, that your volt meter cannot read (mine can read this as spikes at up to 100k times per second. And display it as a peak. I think it comes from the motor commutation /brushes. Theres more than you think, and the control system does see it.

Unless you mean just the batt calibration thing.
I have it if you forgot where it, is PM me...

[emilevirus]

You can set the cloud server ip so you could send data to your own server. Are you aware of anyone using the new PM2 yet?

[snaker]

Generic version won't allow past 25v, Sunrise does.

The Sunrise OEM software allows increasing motor output to 29V. Thanks emilevirus.

[Burgerman]

16 up to 50V can be set in the sunrise software.
But that is PM and firmware dependant. And if you exceed 35v even during a bit of commutator/spark/motor switching emf noise it will stop wih an overvoltage error regardless.

[rover220]

I have here 2 versions that are R-Net GENERIC version 7.0.xxx from two sources inc PG Drives that are both supposed to be the latest.

One is compiled to work with the newer PM2 and has all sorts of battery config options and all sorts of internet connections and spying uploading motor and battery usage parameters and that keeps massive logs...

On the face of it they look the same.

On the options on the left there are a few differences lower down and in the menus.

Take a careful look!
They dont install over the top of each other - both work at at once and are both GENERIC V7.0 in the start menu.

care to share the latest rnet?