S12S vs S09 controller for a 20" folding e-bike

Electric Motors and Controllers
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dapeba   1 µW

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S12S vs S09 controller for a 20" folding e-bike

Post by dapeba » Sep 07 2018 10:49am

Hii everyone!! It's my first post so, first of all i would like to introduce myself. I'm David, i'm from Spain. I'm electrifying a "Moma first class 20 folding bike". I have some doubts about what controller would be better for a q128c motor. I'm heasitating between two models:

1. S09: https://m.es.aliexpress.com/item/32806406829.html
2. S12S: https://bmsbattery.com/ebike-kit/552-s1 ... e-kit.html

The first one would be placed below and the second one above (look at the image attached).

Image

Any recomendation?


Thanks!

-dg   1 kW

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Re: S12S vs S09 controller for a 20" folding e-bike

Post by -dg » Sep 08 2018 4:21am

dapeba wrote:
Sep 07 2018 10:49am
I have some doubts about what controller would be better for a q128c motor. I'm heasitating between two models:

1. S09: https://m.es.aliexpress.com/item/32806406829.html
2. S12S: https://bmsbattery.com/ebike-kit/552-s1 ... e-kit.html
I think the S12S will be too much power for the Q128c. It's more for things like the BPM or the direct drive hubs. The Q128 is a small motor and is likely to overheat or damage the internal gears if run with a 35A controller.

Also, the 12 FET controllers are huge and harder to mount, especially on a bike like that.
If simplicity worked, the world would be overrun with insects.

larsb   10 kW

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Re: S12S vs S09 controller for a 20" folding e-bike

Post by larsb » Sep 08 2018 1:31pm

I've used q128&s12s for a year on road, never any issues. But you need to set the assist lower if you're going in a strong uphill etc.

If you want to have some extra oumph for special occasions then you'll get it with the s12s but the s09 will be better matched to the motor, low risk of burning it and the smaller size is nice.

The low/s09 location is not the best, these controllers aren't really waterproof so it would be best placed away from splashes from ground&wheels

I can't remember now for certain but a s09 could maybe be placed under the saddle..

dapeba   1 µW

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Re: S12S vs S09 controller for a 20" folding e-bike

Post by dapeba » Sep 08 2018 6:07pm

Anyway I see now that the s09 now only exists in square wave right? Anyway, for a 20 inches wheel, I need to run the 328rpm@36V version at 52V, to get a decent ~37kph. 52V and 20 amps must be very damn close to the max of this motor right? I may just try the normal kt36 from pswpower. What do you think?

Thanks!!

larsb   10 kW

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Re: S12S vs S09 controller for a 20" folding e-bike

Post by larsb » Sep 08 2018 9:25pm

I limited most my riding to between 700-1000w, only burst of 1500 once in a while and it got quite warm. I would say that 1000w is about what it can do without overheating on longer term.

I don't know how the BEMF of the q128 motor is, if it's square or sine. Controller should match motor in this regard to get best efficiency.

Edit: i found some waveforms from the s06s & s12s controllers. The sine waveform is not really good :D
I think either controller will suit you.

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Hwy89   1 kW

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Re: S12S vs S09 controller for a 20" folding e-bike

Post by Hwy89 » Sep 09 2018 9:36am

The S12S controller matched with the Q128 hub has been a good combination for me. I now have three bikes set up this way. With the sine wave controller they aer silent and very smooth. The only thing I hear is the tire noise.
The one glitch that I’ve discovered on my most recent build is that the 48 volt controler and the LCD3 display do not like any thing above 56 volts. So if I fully charge my 14S, (52 V nominal) battery I experience annoying overvoltage cut outs until the battery level drops to 55 or 56 volts. I need to reconfigure the battery to 13S but have not done so yet.

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