Possible build using Q128H motor

[Bachgen_o_Gymru]

I'm considering an e-bike conversion for my own use. I'm a big guy; 6 foot 2, and weigh over 14 stone. I live in a moderately hilly area and would use the bike as my main form of transport as I have no car. I'd be doing an average of about 12 miles each day on it. My budget is about £650.

The 48v Q128H motor on BMS Battery looks a good one. I'm not able to post a link for the motor because it causes the thread to get locked into moderation, but if you type the following into google search, it will be the first thing to come up: "Q128H-135mm 800W Rear Driving E-Bike Motor Wheel". Would this motor at 48V provide decent power and torque?

Could anyone recommend a suitable battery, controller, and PAS to go with this motor, preferable also on the BMS Battery site?

I currently have a push bike but it needs replacing, and so I don't have a donor bike available yet. My preference would be one with 20 or 24 inch wheels, based upon the fact that smaller wheels provide for greater torque albeit with a lower top speed.

I'm open to other motor suggestions also, although I'd like to stick with a rear hub setup rather than a front hub or crank setup.

Thanks for any help

 

[Woosh]

the 48V Q128H has excellent torque, plenty to pull 14st up 15% hills on 26" wheels.
I have one of the test bikes fitted with that kit..
If you want to buy from me, I propose the Bafang BPM instead.

 

[Deleted member 4366]

You can either buy a battery from BMSB with the included 20A sine-wave controller or get the 20A sine wave controller separately from PSWPower.com. In my bike I have the Q128C, which has the spline for cassette gears. It's a bit smaller than the Q128H, but even with only a 14 amp controller, it has oodles of power and speed.

If you're going to use 20" wheels, the Q100 will probably be enough, especially at 48v.

 

[Bachgen_o_Gymru]

Thank you for your helpful replies.

You can either buy a battery from BMSB with the included 20A sine-wave controller or get the 20A sine wave controller separately from PSWPower.com. In my bike I have the Q128C, which has the spline for cassette gears. It's a bit smaller than the Q128H, but even with only a 14 amp controller, it has oodles of power and speed.

If you're going to use 20" wheels, the Q100 will probably be enough, especially at 48v.

I had a look at the Q100 and it looks a nice motor, although I think I'd still prefer to stick with the Q128H.
Would you be able to post a link for the battery and included 20A sine-wave controller that you mention from BMSB. I wasn't able to find it when I searched the site. I think it is just me who can't post links on here because my profile is new.

Would there be any particular requirements that a donor bike would need to meet, or would any push-bike do as the donor?

Thank you.

 

[Deleted member 4366]

https://bmsbattery.com/ebike-battery/680-48v116ah-bottle-09-panasonic-battery-pack-battery.html

You can buy the controller/LCD kit separately to use with any battery:
https://bmsbattery.com/controller/698-sine-wave-controller-for-09-case-controller.html

48v, 20 amps and Q128H will be too much for a 20" wheel. I would only think about that for very fat people, and you'd need quite a wide tire to get the traction.

 

[Bachgen_o_Gymru]

https://bmsbattery.com/ebike-battery/680-48v116ah-bottle-09-panasonic-battery-pack-battery.html

You can buy the controller/LCD kit separately to use with any battery:
https://bmsbattery.com/controller/698-sine-wave-controller-for-09-case-controller.html

48v, 20 amps and Q128H will be too much for a 20" wheel. I would only think about that for very fat people, and you'd need quite a wide tire to get the traction.

Thanks. What I'm thinking of is getting the Q128H in a 24" wheel, and the controller/LCD kit that you mention. I'd like the 48V14.5Ah Bottle-10 frame battery to go with it. Is this a compatible combination? I only ask because it mentions that the controller/LCD kit is for the 09 battery case.

 

[1boris]

I have a q128c motor.36v 201 rpm and a 48v battery with 18amp controller.I have two options.27.5 weel or 29 wheel.Any Idea if I will feel any significant loss of torque If I lace the motor into a 29 wheel?

 

[Deleted member 4366]

I have a q128c motor.36v 201 rpm and a 48v battery with 18amp controller.I have two options.27.5 weel or 29 wheel.Any Idea if I will feel any significant loss of torque If I lace the motor into a 29 wheel?

I think it'll be OK. I think 27.5 would be better than 29. There won't be a problem with torque, but you could lose a bit of efficiency with the bigger one. It's perfect with a 26" wheel.

 

[Deleted member 4366]

Thanks. What I'm thinking of is getting the Q128H in a 24" wheel, and the controller/LCD kit that you mention. I'd like the 48V14.5Ah Bottle-10 frame battery to go with it. Is this a compatible combination? I only ask because it mentions that the controller/LCD kit is for the 09 battery case.

That whale battery will require at least one extra rivnut fitted to the frame because it's quite heavy. The more expensive one with the Panasonic cells will be able to provide enough power. The controller is designed to fit the 09 battery mount, but you can install it anywhere and anyhow you want/can.

 

[1boris]

I think it'll be OK. I think 27.5 would be better than 29. There won't be a problem with torque, but you could lose a bit of efficiency with the bigger one. It's perfect with a 26" wheel.

yes I have tried the q128H in a 26 wheel and I agree its perfect So I think I will go with 27.5

 

[Bachgen_o_Gymru]

I think I'll go with the 48V 14.5Ah Case-08 bottle Panasonic battery. It looks a good one and is half a kg lighter than the whale battery I was considering. So if I get this battery, the rear Q128H motor wheel, and the sine wave controller/LCD kit, is that everything that I will need including all the wires and connectors?

One more thing I'm curious about: Is the setup that I've chosen a speed-control one? What I'd prefer not to have is a setup in which the amount of power provided is proportional to the amount of effort that I put in.

 

[awol]

you could lose a bit of efficiency with the bigger one. It's perfect with a 26" wheel.

How would you make that motor (or any other) optimum efficient to use in the bigger 29" wheel? (I still don't understand about the efficiency side of things)

 

[Deleted member 4366]

How would you make that motor (or any other) optimum efficient to use in the bigger 29" wheel? (I still don't understand about the efficiency side of things)

Lower voltage to lower it's speed, or a smaller wheel to make it spin faster. Basically, efficiency drops off rapidly once you drop below 50% of the maximum no-load speed, so the slower the motor, the better the efficiency at low speed. You can make your motor spin to 100mph if you use enough volts or a big enough wheel, but it'll burn out when you use it because it won't have the power to get out of the inefficient zone.

 

[Deleted member 4366]

I think I'll go with the 48V 14.5Ah Case-08 bottle Panasonic battery. It looks a good one and is half a kg lighter than the whale battery I was considering. So if I get this battery, the rear Q128H motor wheel, and the sine wave controller/LCD kit, is that everything that I will need including all the wires and connectors?

One more thing I'm curious about: Is the setup that I've chosen a speed-control one? What I'd prefer not to have is a setup in which the amount of power provided is proportional to the amount of effort that I put in.

You'll need at least one torque arm, and if you buy a complete wheel, it's probably a good idea to buy one of their spoke keys, which will fit the spokes. The ones you buy in bike shops don't fit.

be aware that the fixing points for the 08 battery are in the wrong position for most bottle mounts, so you'll probably need to add your own riv-nuts. Also, that battery has a flat bottom, so it tends to rock on a round frame. For those reasons, I stick to 09 batteries. Whichever one you get, you need to confirm that it can supply continuously the maximum current that the controller allows.