Help! BMSbattery controller confusion

[kaltec]

Originally posted in the ebike general discussion by mistake.
I think here is more appropriate.

Hello (again) oh great pedelec community. I'm in dire need of assistance.

I'm looking to buy a Q128C (500W) or Q100C (350W) 36V rear-hub motor from BMSbattery, as I had a good experience with them some 10 years ago when I built my last electric bike, and the Q motors seem to strike a nice balance between power and lightness. For the sake of discussion let's say that I go with the 500W Q128C motor. Problem is I am thoroughly confused with the controller options, and the controller-display combinations. Can someone help me clear things out and figure what I need to be buying?

I mean, ok, there's the B-series B09P 500W Square Wave controller, which only works with the BMS meters. Pretty straightforward.

But then there are the S-series controllers:
For example, the S06B 20A, which seems to only go with the LCD-TF100 and LCD-TF200 meters.
And the S09PW Torque Simulator Square Wave controller for sensorless motors, which again seems to go with a specific display (S-LCD1). But also the S09P (Torque Sim Square Wave, as well), which "fits all S-series LCD and LED890 meters".
And then there's the S12S 500W Torque Simulator Sine Wave controller for Hall sensor motors, which also "fits all S-series LCD and LED890 meters".
And the S-KU95 controller for the Q128, which only works with the LED810 meter. And the S-KU125. And the S-KU123, which, again, works with the Q128. And the S-KU93. And the latter two I don't know what types of displays they work with.

What are the differences? What does one offer that the other doesn't?
B- vs S-series, square wave vs sine wave, SxxB, SxxS, SxxP, SxxPW, S-KUxx displays, meters, and so on and so forth...

Can someone shed some light on all this for me?
(Or even shed some links I could follow and educate myself)

Thank you all.

 

[Nealh]

It is all about programming and compatibility and branding.

SxxB controllers are China brand Brainwave .

KU are Kuenteng but only analogue led or 3 speed compatible. KU93/123 doesn't use a display just a switch 1,2 or 3. KU95/125 are led only.

SxxP & SxxS controllers are Kuenteng digital for Sseries LCD displays using LCD1 up to LCD10.

BMSB either rebadge branded stuff or have them copied, I don't use them and prefer to use Topbikekit who sell the genuine article or from Greenbikekit & direct off Aliexpress, PSWPower also sell KT stuff but CS is a bit on the poor side.

Sq wave means the signal is a bit rough so controller operation is a bit noisy.
Sine wave is a flattened out signal, controllers run very quietly.

 

[vfr400]

A long time ago, I read that it's not possible to have a sinewave controller with 9 mosfets, so the ones with 9 in the designation are de facto square wave. I have seen controllers with 9 mosfets labelled as sine wave, but i don't know whether this is just sharp practice or genuine.

Anyway, this brings a problem because the 6 mosfet ones are generally 15A. there used to be a 17A one, but i haven't seen them for ages, and there was also a 20A one from PSWPower, but that seems to have gone now to. that means that if you want more than 15A, you have to get a 9 mosfet one, which is probably square wave. The 12 mosfet ones are very big and overkill unless you're heavy and weak.

At 48v, the Q128C is pretty powerful at 15A. I'd be surprised if many normal people need much more power than that on a bicycle. The 17A would be perfect for that motor at 48v on the basis that you can always turn the power down if you don't need it.

The KU series are dual mode. they're very good for motors that don't work very well with other controllers, but not as good ast the S0** sine wave ones.

With the S0** series, you can use any KT LCD, which are mumbered LCD1, LCD3, LCD4, etc. LCD1 is best avoided because it only gives limited access to settings.

 

[kaltec]

@Nealh and @vfr400, thank you so much for your answers, you made everything very clear, and helped me make my picks. In the end I went for the Q128C - 500W motor, a GreenCell battery (36V, 11mAh; I wanted to keep the weight down as much as possible), and a set of controller and paraphernalia from TopBikeKit (T09S SineWave controller with Julei (?) waterproof connectors, a KT-LCD4, a KT-D12L PAS, and a 130X throttle).

This setup brought pure joy to my heart (and legs) for the first 50 or so kms, and still does, however the motor, which was whisper quiet at first, has started to make a whining noise as the speed gets higher, which makes the - steel - frame resonate. Somewhat worrying, maybe not, happened abruptly on a ride after I had stopped for a few minutes. I'm collecting audio and video data of the effect and will probably make a new post asking for you expert advice in due time.

So yeah, that, thank you both again.

 

[Nealh]

My akm128c is quiet so the whine my be that a bit more grease needed inside, I opened mine when new too look and seem to remember adding more. You need to make a special tool to open the case which opens quite easily.
You need a 50mm wide flat bar of a 2 or 3mm thick with a half round cut out, drill two holes to line up with the clutch screws holes on the side plate. screw in two slightly longer machine screws pulled up tight and then use ac/w leverage on the end of the tool, I used a rubber mallet and bashed by bar end.

 

[vfr400]

I didn't use mine for several months when I was ill. It did make a bit of noise when I started using it again, but went quiet after a few weeks. You can only judg what's wrong from the type of noise.