Components advice / feedback for Q128C Build

[Lovelock]

Hi, I'll try make this intro quick.

I was certain I getting a BBSHD and battery from Jimmy (Insat / BGA Reworking) totalling to just shy of £1000.

After speaking to some people on the Pedelecs forum and also seeing some builds using the Q128 rear hub I've decided I don't need the power and price of BBSHD and am excited about getting my head into motors / controllers and sensors etc along with going for a stealthy build.

My new commute is under 7 miles with a maximum hill gradient of around 4%. Pair that with that fact i'm only 5ft 4' and weight < 10 stone I think a 500w rear hub motor is enough considering i'm also using my light road bike.

So, after hours of researching and trying to get my head around everything I settled on the Q128C rear hub. This will be respoked onto my existing rear wheel so will just be buying the hub.

As i'm totally new to this, I need some advice on the controller side of things and required battery specs.

Advice from a member on Pedelecs said there is no controllers really suitable on BMS (where i'm buying the motor) for the Q128c. They linked me to the following controller: http://www.pswpower.com/peng/iview.asp?KeyID=dtpic-2016-3F-33C0.50CGS

I can purchase the PAS etc along with the throttle when I buy the controller. Is this controller suitable for the motor? Or is there a better brand / supplier / spec controller thats better?

Also, going with a 500w motor and any example controller what would the minimum battery continuous output need to be at 48v?

--

A list of current purchase list:

- Motor £91 posted (currently going for higher RPM, feel free to suggest the lower one): https://bmsbattery.com/ebike-kit/768-q128c-135mm-500w-rear-driving-ebike-hub-motor-ebike-kit.html#/43-voltage-48v/214-rpm-328

- Controller £80 posted (including throttle, PAS, Speed sensor and display): http://www.pswpower.com/peng/iview.asp?KeyID=dtpic-2016-3F-33C0.50CGS

I'm not going to use or install the throttle to start with, simply going full PAS to keep this stealthy. The battery and controller with go into my backpack so its really just the motor on show.

For example, this is the first thread I saw that gave me inspiration: http://www.pedelecs.co.uk/forum/threads/q128c-25mph-fast-hybrid-commuter-build-ride-report.29244/

Thanks in advance!

 

[Hwy89]

I use a S12S 500W Torque Simulation Sine Wave Controller from BMS with my Q128 H rear hub. As far as I'm concerned the match is perfect. Everything worked straight out of the box with no mismatched connectors or guessing. The motor runs smoothly and is totally silent. It is quieter than any of my other bikes with DD hubs and non sinewave controllers.

 

[motomech]

Hi, I'll try make this intro quick.

I was certain I getting a BBSHD and battery from Jimmy (Insat / BGA Reworking) totalling to just shy of £1000.

After speaking to some people on the Pedelecs forum and also seeing some builds using the Q128 rear hub I've decided I don't need the power and price of BBSHD and am excited about getting my head into motors / controllers and sensors etc along with going for a stealthy build.

My new commute is under 7 miles with a maximum hill gradient of around 4%. Pair that with that fact i'm only 5ft 4' and weight < 10 stone I think a 500w rear hub motor is enough considering i'm also using my light road bike.

So, after hours of researching and trying to get my head around everything I settled on the Q128C rear hub. This will be respoked onto my existing rear wheel so will just be buying the hub.

As i'm totally new to this, I need some advice on the controller side of things and required battery specs.

Advice from a member on Pedelecs said there is no controllers really suitable on BMS (where i'm buying the motor) for the Q128c. They linked me to the following controller: http://www.pswpower.com/peng/iview.asp?KeyID=dtpic-2016-3F-33C0.50CGS

I can purchase the PAS etc along with the throttle when I buy the controller. Is this controller suitable for the motor? Or is there a better brand / supplier / spec controller thats better?

Also, going with a 500w motor and any example controller what would the minimum battery continuous output need to be at 48v?

--

A list of current purchase list:

- Motor £91 posted (currently going for higher RPM, feel free to suggest the lower one): https://bmsbattery.com/ebike-kit/768-q128c-135mm-500w-rear-driving-ebike-hub-motor-ebike-kit.html#/43-voltage-48v/214-rpm-328

- Controller £80 posted (including throttle, PAS, Speed sensor and display): http://www.pswpower.com/peng/iview.asp?KeyID=dtpic-2016-3F-33C0.50CGS

I'm not going to use or install the throttle to start with, simply going full PAS to keep this stealthy. The battery and controller with go into my backpack so its really just the motor on show.

For example, this is the first thread I saw that gave me inspiration: http://www.pedelecs.co.uk/forum/threads/q128c-25mph-fast-hybrid-commuter-build-ride-report.29244/

Thanks in advance!

Not sure why you would come here when you have the best Q100/Q128 expert @ Pedelecs UK, D8veh (Dave). At any rate, welcome.
You need to study the differences between a Sine Wave and a regular Square Wave controller. The Sine Wave and it's associated display offer more info and rider interface possibilities, while the simple square wave is simpler to set-up and use. Whether or not the Sine Wave "Torque Imitation" controller offers enough benefit over the simple 3-speed limiting controller depends on how much you will be on PAS and the overall power of the system.
I use the a simple 3-speed limiting controller and it works fine for me. I don't run on PAS all the time and when I want to pedal, there are plenty of long straights on my route, that I can just set a speed and pedal along. If I was on Pas all the time, I would be more concerned w/ "response and feel".
There is a bit of a gap in the sine wave line-up for the Q128, ideally, it's controller would be in the 25 to 30 Amp range. The S12S is at the high end, but it's a soft start so that is ok. The prob. w/ it is, it's huge!
The PSW Power KT sine wave that you linked is a good low-powered option. A good square wave equivalent to that controller is the Elifebike 9-fet like I use;
https://www.ebay.com/itm/36V-48V-350W-9MOSFET-ebike-Electric-Bicycle-Brushless-Motor-Controller-with-LED-/222373438918?var=&hash=item33c67d65c6
It's low cost, smooth and gets the job done. They also offer a 20 Amp version that they are currently out of. The 17 Amper can be shunt modd'ed to 23 Amps.

 

[molybdenum]

My new commute is under 7 miles with a maximum hill gradient of around 4%. Pair that with that fact i'm only 5ft 4' and weight < 10 stone I think a 500w rear hub motor is enough considering i'm also using my light road bike.

So, after hours of researching and trying to get my head around everything I settled on the Q128C rear hub. This will be respoked onto my existing rear wheel so will just be buying the hub.

Your commute is fairly flat, but you don't mention how much you like to pedal/fitness level, which has a great impact on your choice of motor, motor wind (RPM at 48V), and battery capacity in Ah. You might get away with Q100 series motors, which are much smaller, stealthier, and can sustain 500W power levels at 48V. I think the Q128 series motors are more obvious on a bike without panniers/big cassette to hide behind, but certainly sufficient for what you are trying to accomplish.

Also, going with a 500w motor and any example controller what would the minimum battery continuous output need to be at 48v?

Some things to consider, and sorry for the dump:

Continuous output (amps) needs to match that of your controller. In the case of the S12S controller, which is ~20A, you would need a battery capable of sustaining at least 20A output (or greater) to avoid over stressing the battery. The controller will only take from the battery the amps it needs. If you wanted to limit power to 500-600W, your controller would be programmed to max out at 12-14A instead of 20A (12A x 48V = 576W. Full 20A controller output would yield almost 1000W at 48V. I can't speak for other BMS battery controllers, but I know that the S12S can be programmed through the LCD interface and the torque simulation PAS comes with high acclaim. It's still a good idea to get a battery capable of sustaining at least 20A (more is obviously better), as this will extend the lifetime of your pack and should you choose in the future to go to higher power, you can use the same battery.

You need to buy a battery with name brand cells. Panasonic, Samsung, LG etc make cells with high capacity, which result in a ligher pack for given Ah. If you can find a local supplier/builder that uses name brand cells, this is best, as damaged batteries cannot be shipped internationally. Stil, there are international suppliers that I would consider, such as EM3EV, which makes excellent quality batteries and have a variety of choices in cells: https://em3ev.com/shop/?product_cat=ebike-battery-in-case.

Do not but mystery packs from aliexpress or ebay if you don't know what cells they use. Also, after-purchase support from these vendors tends to be brutal to nonexistant. The BMSB panasonic (NCR18650PF) packs are OK but are a bit heavy for the Ah they provide, only come in "bottle" format, and they do not have imo the workmanship/quality of the EM3EV batteries.

Given that you want to carry it in a backpack, you will want to keep weight down and purchase a smaller pack; hence paying a bit extra for a battery made from higher density cells such the High Energy – Samsung 35E cells would make your ride much more comfortable and provide greater capacity for a given weight.

In general, if you minimize discharge to 30% and avoid running the pack to "empty", you can extend its life and get many more charge cycles before the eventual loss of capacity. Charging to 90% of full will further extend the pack's lifespan, and many reputable dealers including EM3EV sell chargers and batteries with the capacity for 90% charging with the aim of extending pack lifetime.

 

[Lovelock]

Some things to consider, and sorry for the dump:

I appreciate the dump! Its exactly what i'm looking for. Speaking to D8veh over on Pedelecs has given me a whole host of info and i'm slowly understanding the wattage calculations and capacity of the motors.

I'm going with the Q128c @ 48v and 328RPM. He advised going for the 17a controller 'kit' from PSW power but I would rather get both the controller and motor from the same place to save on some shipping. Hearing the possibility that I can cut the ampage pulled from the battery means I could go for the 20a S12S from BMS.

I'll be speaking to Jimmy from Insat to get a price on a 48v battery that can output a continuous 25-30a so that I have enough to cover myself for any future projects.

The controller as it is 20a at 48v will be pushing around 960w to the motor. Does this sound okay for it to handle? How do you determine the maximum a motor can handle or is it just a case of knowledge / others testing the limit.

My current basket on BMS is:

These should all play nicely right? Is there anything else I need?

Also, I have no idea which PAS sensor will work? 12 hall / 10 means nothing to me currently.

 

[motomech]

If you want a sine wave then, as usual, Dave is correct. The KT from PSW Power and you just have to bit the bullet and make two orders. It's not that much to ship a controller only. You can save some shipping by ordering your batt from BMS Battery. You know Dave is a fan of the Panasonic cell batt. from them.
When ordering from BMS Battery, it's a good idea to stock up on the sm. stuff, which not counting freight, costs almost nothing. I would include;
spoke wrench
2) pr. torque arms(get right size)
and definately
left-hand, half-twist throttle.
When communicating w/ them, make them repete the the exact motor you want.
The PAS disc will come w/ the controller.
960 Watts is no problem at all that motor, I run 20 Amp controllers on my Q100's and they are smaller than the Q128. If anything, the 17 Amper is too low a rating for that motor, I use go w/ the 20 Amp version.

 

[molybdenum]

If you want a sine wave then, as usual, Dave is correct. The KT from PSW Power and you just have to bit the bullet and make two orders. It's not that much to ship a controller only. You can save some shipping by ordering your batt from BMS Battery. You know Dave is a fan of the Panasonic cell batt. from them.
When ordering from BMS Battery, it's a good idea to stock up on the sm. stuff, which not counting freight, costs almost nothing. I would include;
spoke wrench
2) pr. torque arms(get right size)
and definately
left-hand, half-twist throttle.
When communicating w/ them, make them repete the the exact motor you want.
The PAS disc will come w/ the controller.
960 Watts is no problem at all that motor, I run 20 Amp controllers on my Q100's and they are smaller than the Q128. If anything, the 17 Amper is too low a rating for that motor, I use go w/ the 20 Amp version.

I've not tried the KT controller but I agree with motomech and D8veh that it is the better option. I see the one linked above is the 20A version. My S12S seems to operate at 20A with default programming and can be adjusted down to 50% of max. This works out to a minimum adjustment to about 580W on a fully charged 48V battery. Since this is all the power I need, I've run my S12S at the minimum setting since I got it a couple years back. My only complaint is that it is honking big. It hasn't escaped me that BMSB now lists the S12S as a 25A controller. It was listed as a "500W" controller when I purchased it, and they made no mention of max amps, 25A or otherwise.

I've been using the BMSB panasonic battery for approx 300 charge cycles and it has been without problems and no noticeable loss of capacity.

Definitely a good call on stocking up on small items such as throttles etc.I have a bunch of spare parts lying around to prevent down time. Left hand throttle is best as it spares the right hand to operate the rear cassette.