Controller recommendation for good PAS experience

[Compuatic]

All,
I converted a mountain bike to E using a standard china 1000W rear hub kit. Specifically I used the Voilamart kit with the SW900 display and it works well.

The main issue is the PAS experience. I was really hoping for "true" PAS similar to other off the shelf E-Bikes. The kit has a the standard ring type PAS sensor and the controller uses it as essentially an on/off switch.

So currently,
1. You start to pedal, the motor goes to full power.
2. PAS level (selectable on the screen) is basically a max speed setting, no impact to power.

so it's basically a cruise control feature that kicks in as soon as you pedal.

I realize that my system lacks a true torque sensor, however i've read little information on "torque simulating sinewave controllers" ? and other things but the literature is sparce with little information on specific controllers and how they behave. BMSbattery controllers? KT controllers?

I would love a recommendation on what I can do or change to get the desired PAS experience i am looking for. I appreciate the help.

 

[sleepy_tired]

I am no expert in this as I really have only ridden one style of PAS. So don't be surprised if everything I say is 100% wrong.

But there are two common methods of PAS control:

1. Speed limit.

2. Power limit.

So a lot of the cheap kits only have speed limits. So different 'PAS levels' really means different speeds the motor cuts off at.

The 'Torque Simulation' style is the power limit-style. So different PAS levels provide different throttles and it doesn't care what speed you are going. It just provides a constant power. Raise the PAS level and you raise the throttle limit.

I think nicer cadence-style setups have a slope or delay of power delivery based on how fast you are spinning the pedals.


My personal experience is with the Cycle Analyst v3 were I just set the PAS limit to 350 watts. Seems like a good balance between 'jerky start' and 'how fast I want to be able to go when pedaling'. When I hit a hill or need a boost of power/speed I can then just use my hand throttle.

 

[niwrad]

i use a phaserunner, but really have to say cycle analyst is what made the experience worthwhile the most.

It has a PAS feature that includes scaling with cadence, as well as multiple programmable set points. This allows me to have almost as seemless a motor control as a torque sensing PAS, but without having to drill a hole into my bottom bracket. Basically I have three "modes", economy, middle, and high. I set the "initial" power to be something just enough to get me going, but then it as a feature to scale with cadence, so at 100 RPM pedaling, I'll get say additional 50% power, or if Id like to go slower, then 50 RPM for 25% additional power. Obviously these aren't my exact numbers but it does make it feel pretty natural, and if I need more torque, say for hills, I use the cycle analyst to toggle into one of my higher modes, which would give even more initial power.

 

[amberwolf]

If the controller in your kit is a KT Kunteng Kun Teng controller, you may be able to use the open-source firmware by Casainho et al. to get better control. I havent' used it, so you'll have to find his thread and read thru it (there's a lot!) to see if it will do what you want.

Otherwise, you can simply buy the Cycle Analyst v3 from http://ebikes.ca and wire it into your existing kit per the guides linked on the CA v3 info page on that site, to use cadence PAS sensor control over the system. You can adjust it to operate in several ways, including a switch to give you presets for different situations. There can be a lot of tuning to get it where you want, but it's possible.

There's a very long thread about the Cycle Analyst v3 "beta" discussing the many versions of firmware it's gone thru and various options it has, and use cases people have worked out, that may be useful for you if you go that route.

 

[AHicks]

I'm not sure if you can get into the setup on the SW900, or how, but my guess is that's where your issue lies.

What you have going on is not normal.

If you're looking for a new controller and display combo, I like the KT based controllers and LCD3 display for good control. A good compromise between not enough control and too much. You don't need an electrical engineering degree to program it.

 

[Compuatic]

Thanks for the feedback.

lots of recommendations to try the cycle analyst. Is this compatible with any controller?

If i am interested in a KT based controller, any recommendations on where to purchase?

Is the BMSBattery S series controller the same as the KT?

 

[amberwolf]

lots of recommendations to try the cycle analyst. Is this compatible with any controller?

Yes. If you get the CA v3 SA model, it has it's own shunt and speedometer sensor, so you don't need any special connectors on the controller. The only thing you may have to change is the connector type on the throttle, brakes, and PAS sensor, at both controller and device end, so they match the ones on the CA (easier than changing the CA plugs to match the ones on the controller and devices, usually).

If your controller has the "CA (DP) connector" you can use the CA DP model that uses the controller's shunt and speed sensor (if it's a DD hubmotor--if it's a geared hub or middrive then you need the CA DP with speedo sensor).

On the CA v3 page at http://ebikes.ca there are links to videos and documents like the UUG that can walk you thru the complete setup; it *is* a complicated device with many interdependent settings, and fine tuning it to do exactly what you want can take a while, and patience. (sometiems it's easy and quick...but not always, like on my SB Cruiser I've been trying for a long while, bit at a time, to get it where I want it).

 

[Compuatic]

Is there a way to tell if my current controller is KT based? This is how it looks like.

 

[amberwolf]

Can't tell from that label, or the casing. KT Controllers will generally have KT in the model number, and say Kun Teng or Kunteng in the manufacturer name.

My guess is it is not KT, simply because it uses the SW900 LCD, which is for a different brand of controller (Li Shui, IIRC, usually with LS in the controller model number).



FWIW, lots of companies use controllers from other companies and peel off the old label and put their own on. Sometimes you could still tell by opening it up, but you'd have to know what the KT looks like inside. I wouldn't do that, unless you're willing to risk damaging the controller (breaking wires, etc) or making it completely inoperable. If you do, you'll have to look in the KT threads to see if there are pics you can use as a guide to tell.

 

[wturber]

2. PAS level (selectable on the screen) is basically a max speed setting, no impact to power.

The PAS level (they call it "gears") on my KT controller/LCD5 map to five different levels of motor wattage. My general riding experience is very bike-like IMO. It is like riding with adjustable levels of tailwind/downhill (or anti-downhill).

I tried the torque simulation feature and concluded that it was crap. At least it was with my inexpensive squarewave controller. It seemed to work counter to my intentions giveing more power when I didn't want it and less when I did. Maybe the sinewave controllers do better? I dunno.

 

[Compuatic]

2. PAS level (selectable on the screen) is basically a max speed setting, no impact to power.

The PAS level (they call it "gears") on my KT controller/LCD5 map to five different levels of motor wattage. My general riding experience is very bike-like IMO. It is like riding with adjustable levels of tailwind/downhill (or anti-downhill).

I tried the torque simulation feature and concluded that it was crap. At least it was with my inexpensive squarewave controller. It seemed to work counter to my intentions giveing more power when I didn't want it and less when I did. Maybe the sinewave controllers do better? I dunno.

Where did you buy your KT controller and which version do you have? I also have a generic Chinese 1000W rear hub. Is it sine or square wave?

 

[E-HP]

Where did you buy your KT controller and which version do you have? I also have a generic Chinese 1000W rear hub. Is it sine or square wave?

You can get one on ebay, but you have to look at the label. I got one like this, and the ad also said "Risunmotor", but it's a KT sine wave. If you use the zoomed view, you can just make out the model number, to me, sort of looks like "KT36/48SV.....", and I believe those are the voltages, and SV is the sine wave part.

https://www.ebay.com/itm/Risunmotor-36V-48V-1500W-Ebike-Brushless-DC-Sine-Wave-Controller-LCD-Panel/182069747537?hash=item2a6433df51:g:zKgAAOSwEjFXcg-P

 

[wturber]

Where did you buy your KT controller and which version do you have? I also have a generic Chinese 1000W rear hub. Is it sine or square wave?

It's an ebay kit. If your motor makes a kind of ringing noise under throttle, then you have a square wave controller. Sinewave controllers are (I'm told) pretty much silent.

 

[rote]

Compuatic,
My first kit included one of those 'DC Moto' controllers and SW900 displays. (DC Moto is not KT.) Yes, the PAS settings with this setup is harsh. I liked the look and features of the KT-LCD3 display so I ordered one thinking it would work with the DC Moto controller. Unfortunately it didn't, so I ended up buying a KT controller too.

I think my KT controller is square wave but in any case the PAS is much better than the DC Moto/SW900 PAS. KT PAS is much smoother (not jerky). I'm not certain but I think KT uses the term 'torque simulation' for PAS for both their square and sine wave controllers. You can get KT controllers and displays on ebay, aliexpress, etc.

 

[AHicks]

Have a look at this controller. It says square wave all over the listing, until you get down to the "advantages", where it says it's a sine wave. I've been running this one for a while now (over a year) and there is no "pinging" typical of a square wave. It's quiet.

With 12 mosfets and a max 35a rating, it should have plenty of capacity for your motor, without being physically huge.

It's inexpensive and you can order it with any KT display available, along with any other options you want. Good customer support too.

http://www.pswpower.com/ven.php?cargo.2016-3f-28ym