What e-bike controller

[vladobac]

Hello everyone.
I have a bicycle with a 36V/250W rear motor with the marking CZJB26" 36VS24225455. The motor also contains Hall sensors and has a 9-pin round connector. The controller has a maximum of 15A on the label, marking 36VLD6G. It has 5 levels of support, switched by buttons on the handlebars and indicated by 5 LED diodes. Without a display. The motor is activated by the PAS sensor or throttle. I am a more active cyclist and ride up to 10,000 km per year, mostly on the flat. I most often use only the 1st level of support, so that I can also get some exercise and increase the bike's range. I don't like that this controller helps too much even at the lowest assistance and has an uneven ride. It quickly overheats on hills when using stronger assistance. However, its great advantage is the unlimited speed at all assistance levels. In practice, even at assistance No. 1, the bike forces me to engage the heaviest gear in order to be able to contribute to the movement of the bike. In lighter gears, I only imitate pedalling, because the motor does all the work and it only needs me to activate the PAS sensor. So I practically ride permanently in the heaviest gear, which of course wears out unnecessarily quickly.

I measured the current draw from the battery for each assist:
Assistance No. 1 draw 5.6A (at 36V 202W!)
Assistance No. 2 draw 8.2A (295W)
Assistance No. 3 draw 10.2A (367W)
Assistance No. 4 draw 12.5A (450W)
Assistance No. 5 draw 16A (576W)
It is clear that assistance No. 1 is unnecessarily oversized for an active cyclist. I contacted the bike dealer and he wrote back that the manufacturer told him that it could not be changed. I think that support would suit me, for example, something like this: 100W, 150W, 200W, 350W, 500W.

I am looking for a controller with a weaker initial assistance (ideally adjustable), smooth operation and, most importantly, without a speed limit. Price approx. €100 for controller + display. I do not want my motor to turn off when I am actively helping it.
Thank you for your tips.

Vladimír

 

[E-HP]

I am looking for a controller with a weaker initial assistance (ideally adjustable), smooth operation and, most importantly, without a speed limit. I do not want my motor to turn off when I am actively helping it.

There are a lot of options. The options narrow depending on your skill set. Controller wiring is not standardized, so swapping out connectors and/or reordering the conductors could be necessary requiring soldering/crimping, etc, and use of a multimeter to troubleshoot with. Do you have soldering iron, crimpers, etc?
If you need something More plug n play, then knowing (seeing) what is in place now and the wiring will be necessary, not just words,

What are your limitations and skills? If you need plug n play, this sticky provides guidance on how to post links and pics.
Thread 'Troubleshooting sticky (work in progress)'
https://endless-sphere.com/sphere/threads/troubleshooting-sticky-work-in-progress.128411/

 

[derekderek]

ok, you have an old school controller and display. you want to get a controller-display combo. this cheapie I have had good luck with. Amazon.com : 24V 36V 48V Ebike Controller Kit 500W 25A Brushless Motor Controller and Ebike Display Scooter Controller with LCD Screen Electric Bike Controller Electric Bicycle Speed Controller for Brushless Motor : Sports & Outdoors s866 protocol. plenty of amps for your setup. we see 35 mph with essentially same bike and 500 watt motor with upgrade to 48 volts. once you have an actual display you can go into and adjust you will find you can set what you want for PAS sensitivity and time lag to start the one thing I don't like is the 2 wires coming off display for lights? they don't exist. so it takes a bit of creativity to make lights work and shut off.

 

[SlowCo]

Maybe a 'shunt mod' would also work. Normally people want more amps from a controller so they reduce the resistance of the shunt in the controller by adding some solder. In your case you could file (remove) some material from the shunt wire to increase the resistance. The controller will then decrease the amp output in all (!) settings.
See here for shunt mod thread

 

[stancecoke]

ideally adjustable

The Lishui controllers let you define the power for each level individually.
See the manual of the display, how to set:

https://share.google/rLOQgDj6NGmwlVCxg

But I recommend to upgrade to a torquesensor system, it provides a much more bicycle like feeling than simple PAS assistance...

 

[vladobac]

There are a lot of options. The options narrow depending on your skill set. Controller wiring is not standardized, so swapping out connectors and/or reordering the conductors could be necessary requiring soldering/crimping, etc, and use of a multimeter to troubleshoot with. Do you have soldering iron, crimpers, etc?
If you need something More plug n play, then knowing (seeing) what is in place now and the wiring will be necessary, not just words,

What are your limitations and skills? If you need plug n play, this sticky provides guidance on how to post links and pics.
Thread 'Troubleshooting sticky (work in progress)'
https://endless-sphere.com/sphere/threads/troubleshooting-sticky-work-in-progress.128411/

I'm an electrical engineer, so I have the equipment. I just don't have any experience with e-bikes. I got into it a few months ago when I bought an e-bike for my wife to use on trips together. So that's why I'm asking the more experienced ones.

 

[vladobac]

Maybe a 'shunt mod' would also work. Normally people want more amps from a controller so they reduce the resistance of the shunt in the controller by adding some solder. In your case you could file (remove) some material from the shunt wire to increase the resistance. The controller will then decrease the amp output in all (!) settings.

Interesting idea. I might try that. Thanks.

 

[vladobac]

The Lishui controllers let you define the power for each level individually.
See the manual of the display, how to set:

https://share.google/rLOQgDj6NGmwlVCxg

View attachment 380122

But I recommend to upgrade to a torquesensor system, it provides a much more bicycle like feeling than simple PAS assistance...

I'll look into it, thank you.

 

[vladobac]

ok, you have an old school controller and display. you want to get a controller-display combo. this cheapie I have had good luck with. Amazon.com : 24V 36V 48V Ebike Controller Kit 500W 25A Brushless Motor Controller and Ebike Display Scooter Controller with LCD Screen Electric Bike Controller Electric Bicycle Speed Controller for Brushless Motor : Sports & Outdoors s866 protocol. plenty of amps for your setup. we see 35 mph with essentially same bike and 500 watt motor with upgrade to 48 volts. once you have an actual display you can go into and adjust you will find you can set what you want for PAS sensitivity and time lag to start the one thing I don't like is the 2 wires coming off display for lights? they don't exist. so it takes a bit of creativity to make lights work and shut off.

I looked at the YT controller settings using the S866 display and I only saw one speed limit setting (parameter P08). Does it apply to all assistance levels? So if I choose assistance level 1 and help the bike a lot, will the assistance never turn off?
And I also didn't see the assistance strength settings for individual levels.

 

[vladobac]

I also read about sine wave controllers. They are said to be quieter and more efficient. Is the difference noticeable in practice and is it worth the money? My budget for this modification is about €100.

 

[stancecoke]

I also read about sine wave controllers

Yes, they are much quieter especially at high load during acceleration or uphill.
The efficiency is better also, but that's only marginal.
What display is on your bike? If you want to change the controller, you have to use a suitable display for is, as many different bus systems and protocols are used.
A "better" FOC controller with a display for 100€ is possible, if you buy in China directly.

 

[vladobac]

Now I only have the LED assistance indicator. But I found such a controller with a display on Aliexpress. 25ASineLCD5. Do you think it would meet my requirements?

https://www.aliexpress.com/item/1005009224952137.html?spm=a2g0o.cart.0.0.547138daJe8Cui&mp=1&pdp_npi=5%40dis%21EUR%21EUR%2065.31%21EUR%2065.31%21%21EUR%2065.31%21%21%21%400b830cc417623713882708386e797a%2112000048397584805%21ct%21SK%21134476599%21%211%210

 

[docw009]

Yes, bikes being too powerful in PAS 1 is a common complaint,

Using a higher resistance shunt is a good low cost suggestion. If you double the length by adding more wire, should be half the current,. Easily restored to normal too..

 

[vladobac]

Or what would you recommend for around €100 for the controller + display to meet my requirements?

 

[vladobac]

Yes, bikes being too powerful in PAS 1 is a common complaint,

Using a higher resistance shunt is a good low cost suggestion. If you double the length by adding more wire, should be half the current,. Easily restored to normal too..

View attachment 380135

Thanks for the inspiration, I'll try it. I'll just have a lot of trouble taking it apart. It's sealed in silicone.

 

[E-HP]

Thanks for the inspiration, I'll try it. I'll just have a lot of trouble taking it apart. It's sealed in silicone.

So you are ok with less hill climbing assist in order to have lower assistance on the lowest assist level, correct?

 

[vladobac]

So you are ok with less hill climbing assist in order to have lower assistance on the lowest assist level, correct?

I think not.

 

[E-HP]

I think not.

A shunt mod fools the controller into thinking more current (or less, depending on the mod) is flowing than there actually is. It will affect all assistance levels.

 

[vladobac]

I also have a small resistance meter. I just need to get some Constantan resistance wire of the right thickness.

 

[vladobac]

FOC controller

What is an FOC controller?

 

[E-HP]

If you end up replacing the controller, you’d want to get one where the throttle control mode (applies to both throttle and PAS) is either current or power, and not speed. Speed controllers will apply full power until it reaches the speed that is associated with the throttle position, then decrease power after hitting that speed. It’s not a natural feeling, like flooring your car at the light, then letting off once you get to the speed limit.
I have some related info in my DIY newbie FAQ.

“Throttle Control Modes - The controller's MCU determines how a throttle input signal translates to output to the motor. It may do so by taking the throttle input voltage and translating that to a target RPM (speed), or to power, or current (torque). The mode may dramatically change how the motor responds to a throttle input.
Many budget controllers use an RPM based throttle control. Under this type of control, the controller will output full power until it achieves the target RPM and then drops the power to maintain that RPM/speed. This can make both the PAS, and especially throttle, difficult to control, with a feeling of the motor surging or pulsing, but may be preferred under certain applications.“
Most programable controllers, as well as the Cycle Analyst, have the ability to change between throttle control modes to the user's preference. Note that since the Cycle Analyst operates under a closed loop (monitors voltage, current, and speed), it can implement all three control modes even when the controller's native mode is speed based.

 

[vladobac]

Ak nakoniec vymeníte ovládač, mali by ste si zaobstarať taký, v ktorom je režim ovládania škrtiacej klapky (platí pre škrtiacu klapku aj PAS) buď prúd, alebo výkon, a nie rýchlosť.

I agree, but give me some specific tips under €100. The price of my bike was €579, so it's pointless to invest, for example, €300 in it...

 

[E-HP]

I agree, but give me some specific tips under €100. The price of my bike was €579, so it's pointless to invest, for example, €300 in it...

You can look at the display manuals for whatever controller you're considering to see that there are parameters to make adjustment to amount of assistance they provide.

The KT controllers you referenced have a couple of ways to adjust power and assist in their setup menu, and have selectable power/current/speed control modes.

 

[stancecoke]

What is an FOC controller?

FOC stands for field orientated control. It's a special form of sine wave commutation that minimizes the losses and maximizes the torque.
It's the standard for modern BLDC controllers. You can get them from about 30€ for scooters e.g.

give me some specific tips under €100

This is a bundle of a Lishui FOC controller and a display, but it's sold out at the moment, I think.

https://www.aliexpress.com/item/4000038619326.html

 

[vladobac]

Thanks for the tip. I'll think about it. I see it has an input for a torsion sensor. Would this controller work temporarily with a PAS sensor?