Brompton Cute Q70 question

Paradad · Nov 9, 2019

So let's look at a recipe for about 10km range :
Q70 - MOTOR (thanks Tom)
KT sinewave controller with brake cutoffs and PAS - CONTROLLER
KT LCD4 Screen - small and neat - SCREEN (Thanks @vfr400 )
Small 36v 5.8 Ah bottle battery - BATTERY (ditto!)
Bag for the battery - BAG
Spokes Calculator
Rim
This post has got me interested & I'm thinking of putting this together - maybe with a bigger battery but I think this would give a pretty and useable set up.
Thoughts?

Collis123 · Nov 9, 2019

Paradad said:
So let's look at a recipe for about 10km range :
Q70 - MOTOR (thanks Tom)
KT sinewave controller with brake cutoffs and PAS - CONTROLLER
KT LCD4 Screen - small and neat - SCREEN (Thanks @vfr400 )
Small 36v 5.8 Ah bottle battery - BATTERY (ditto!)
Bag for the battery - BAG
Spokes Calculator
Rim
This post has got me interested & I'm thinking of putting this together - maybe with a bigger battery but I think this would give a pretty and useable set up.
Thoughts?

How straight forward do you think it will be to add the motor to the rim and spokes?

And having used a Swytch kit that is limited at 15mph, I recommend a bigger battery to give you a bit more juice on the flats. Just put the battery in a front bag because it will probably be too heavy to mount on the handlebars.

vfr400 · Nov 10, 2019

You don't need a bag for the battery. It's fully waterproof. Just fit a bottle holder on the handlebars or wherever you want it. If you're going to use a bag, a bare cell-pack with BMS will be a lot cheaper.

Paradad · Nov 10, 2019

Hi @Collis123 , got be honest, haven't done it for years. I used to find wheel building tough but satisfying.. I'd only do it now if i couldn't buy what i need ready made. In this instance I think I'll do it to use the q70 - and to be sure of a good quality front wheel. In this case the kits on ebay are just too much of an unknown quantity for me. I know there will be much swearing ahead if I get started....

@vfr400 - yup, good point. bag not needed but i think is looks pretty& is also convenient option for carrying the battery about off the bike. That said I am looking at alternative batteries. I share concern about range, so I'm still lookin at that. The rest of it looks okay to me. Im tempted to start hitting the "sod it" buttons and start ordering soon.
That said I just found a thread on this forum of interest. Same idea using a fatter motor:

Wheel Building - Tongxin in Brompton wheel

jerrysimon. Use a pipe cutter on the shaft, use a file first on the shaft to make a small indent so the cutting wheel can sit flush. Good luck MAPMAN.

www.pedelecs.co.uk

Collis123 · Nov 10, 2019

Paradad said:
Hi @Collis123 , got be honest, haven't done it for years. I used to find wheel building tough but satisfying.. I'd only do it now if i couldn't buy what i need ready made. In this instance I think I'll do it to use the q70 - and to be sure of a good quality front wheel. In this case the kits on ebay are just too much of an unknown quantity for me. I know there will be much swearing ahead if I get started....
@vfr400 - yup, good point. bag not needed but i think is looks pretty& is also convenient option for carrying the battery about off the bike. That said I am looking at alternative batteries. I share concern about range, so I'm still lookin at that. The rest of it looks okay to me. Im tempted to start hitting the "sod it" buttons and start ordering soon.
That said I just found a thread on this forum of interest. Same idea using a fatter motor:

Wheel Building - Tongxin in Brompton wheel

jerrysimon. Use a pipe cutter on the shaft, use a file first on the shaft to make a small indent so the cutting wheel can sit flush. Good luck MAPMAN.

www.pedelecs.co.uk

Let us know what you decide to do! I can't reiterate enough how much I don't think the battery you have selected will be sufficient (unless you are only planning on going very short distances). The predicted range is never as good as expected in reality.

Collis123 · Nov 10, 2019

What about one of these batteries? Would give you the extra range and speed? There might be a smart way of mounting it on the front of the bike above the wheel. Going to cost a bit more money, but you could come up with something pretty impressive?

48V10Ah/11.6Ah/14Ah Li-Ion Alloy 01-Case EBike Battery Pack Color Black Cells / Capacity SAMSUNG 3.5AH / 14AH

36V15Ah Li-Ion NiCoMn aluminium alloy sheel electric bicycle battery pack. Included 10s polymer cells, 1pcs 15A continuous discharge current smart BMS, 1pcs ...

bmsbattery.com

48V12.5Ah/14.5Ah/17.5Ah Bottle-10 Frame E-Bike Battery Pack With USB Output Cells / Capacity SAMSUNG 3.5AH / 17.5AH

New design bottle-09 ebike panasonic NCR18650PF battery pack 36V14.5Ah included a S180 charger.

bmsbattery.com

Or this one if you want to save money and just place it in a bag? This is smaller as well.

48V10Ah Li-Ion Shrink Tube EBike Battery Pack

48V10Ah Li-Ion NiCoMn shrink tube electric bicycle battery pack. Included 13s polymer cells, 1pcs 15A continuous discharge current smart BMS, 1pcs 48V3mps S1...

bmsbattery.com

Paradad · Nov 10, 2019

@TomCC - you've stayed very quiet

So, inspired by this thread I've decided to go for a 36v 10AH Hailong battery and the Cute Q70. It won't be as pretty as some but I think will work well enough on the cross bar and shouldn't interfere with folding while also giving me the longer range I'm looking for. @Collis123 I think 48v may be too much for this wee motor & personally I'd be concerned about over heating. My main aim for this is to avoid sweatyness rather than increase speed, so 36v it is.
I'll let you know how I get on in a few weeks from now...

vfr400 · Nov 10, 2019

Paradad said:
@TomCC - you've stayed very quiet So, inspired by this thread I've decided to go for a 36v 10AH Hailong battery and the Cute Q70. It won't be as pretty as some but I think will work well enough on the cross bar and shouldn't interfere with folding while also giving me the longer range I'm looking for. @Collis123 I think 48v may be too much for this wee motor & personally I'd be concerned about over heating. My main aim for this is to avoid sweatyness rather than increase speed, so 36v it is.
I'll let you know how I get on in a few weeks from now...

I think you'll find that battery and the ones in the post above yours too big and heavy for a Brompton. Personally, I wouldn't go any higher than 30 cells (1.5kg). 30 cells can get you a good 9Ah, which would take you at least 30 miles of moderately hilly riding without sweating.

The guy who rides the Brompton I converted said that even with a 30 cell battery, the bike was still too heavy to carry anything much more than into the boot of a car. He concluded that if you want to fold and carry the bike, a removable battery would be essential.

Jonah · Nov 10, 2019

vfr400 said:
I think you'll find that battery and the ones in the post above yours too big and heavy for a Brompton. Personally, I wouldn't go any higher than 30 cells (1.5kg). 30 cells can get you a good 9Ah, which would take you at least 30 miles of moderately hilly riding without sweating.

The guy who rides the Brompton I converted said that even with a 30 cell battery, the bike was still too heavy to carry anything much more than into the boot of a car. He concluded that if you want to fold and carry the bike, a removable battery would be essential.

I concur, small and light suits the Brompton best, in a small removable bag on the luggage bracket. 30 cells would give you 10.5ah with decent cells. Also, now that narrower motors are available I would avoid the options that require stretching the forks.

Collis123 · Nov 10, 2019

Jonah said:
I concur, small and light suits the Brompton best, in a small removable bag on the luggage bracket. 30 cells would give you 10.5ah with decent cells. Also, now that narrower motors are available I would avoid the options that require stretching the forks.

I tend to disagree. I used the swytch kit for a while and that was about 3.5kg or maybe even 4. As long as you mount it low down by the wheel it will have a low centre of gravity and you won't even feel the extra weight.

vfr400 · Nov 10, 2019

Collis123 said:
I tend to disagree. I used the swytch kit for a while and that was about 3.5kg or maybe even 4. As long as you mount it low down by the wheel it will have a low centre of gravity and you won't even feel the extra weight.

Do you fold it frequently? If so, how do you deal with it? How many cells in your battery?

Jonah · Nov 10, 2019

Collis123 said:
I tend to disagree. I used the swytch kit for a while and that was about 3.5kg or maybe even 4. As long as you mount it low down by the wheel it will have a low centre of gravity and you won't even feel the extra weight.

My 10ah Swytch kit is 3.5kg but mounts on the handlebars. I find it ok because it’s so much lighter than the Sparticle kit I had previously (about 9kg) which was mounted on the luggage bracket. A heavy weight on or over the front wheel, even if low down noticeably effects handling. 3.5kg isn’t bad but 2kg is better. I wouldn’t want much less than 10ah though.

Collis123 · Nov 10, 2019

Right. If I was thinking of DIY'ing a brompton now I would seriously consider just waiting for the new Swytch kit that will be available next year. The battery is tiny. Not going to be possible to DIY anything close atm.

vfr400 · Nov 10, 2019

Collis123 said:
Right. If I was thinking of DIY'ing a brompton now I would seriously consider just waiting for the new Swytch kit that will be available next year. The battery is tiny. Not going to be possible to DIY anything close atm.

The Swytch kit just uses standard battery cells and motor. The kit gives an easy solution, but you can get the same yourself. The battery is just a a 20 cell one using 2500mAh cells, like Samsung 25R to give 180Wh. That's enough for about 15 miles with some hills. the larger capacity battery will use 3500 mAh cells. I hope they chose those wisely. The motor shown in their photos is a Q100 (Q70 for narrow forks).

wheeliepete · Nov 10, 2019

If you are looking for lightweight with decent capacity this might be worth considering in 10S2P format as long as you are not running over 15 amp controller.

Softpack Battery 36V 10Ah BMS 20A XLR-3 with M50 5x4

ENERpower Softpack battery 36V, format 10S2P, square) | 360 Wh | capacity 10 Ah | for Pedelecs, eBikes DIY | LG Chem M50. Important General…

enerprof.de

vfr400 · Nov 10, 2019

wheeliepete said:
If you are looking for lightweight with decent capacity this might be worth considering in 10S2P format as long as you are not running over 15 amp controller.

Softpack Battery 36V 10Ah BMS 20A XLR-3 with M50 5x4

ENERpower Softpack battery 36V, format 10S2P, square) | 360 Wh | capacity 10 Ah | for Pedelecs, eBikes DIY | LG Chem M50. Important General…

enerprof.de

That pack uses 21700 cells so a lot bigger than 18650s. It's more or less equivalent to a 30 cell 18650 pack.

Paradad · Nov 10, 2019

Oh now you've almost made me wish I'd held back a little longer!

However, I'm commited now. It's a fair point about the weight for carrying - and partly with that in mind I was considering a set of two (or more) smaller batteries which could be very effective (I think the bottle with that grey case from rockbros looks like a great combo). However - I very rarely carry my Brompton anywhere. It lives in the back of the car and comes out when I get to the city limits so I wanted enough power to get in and out with a bit to spare. I *think* it'll look Okay but I'll post some photos later and let the pedelecs community judge !
The key factors for me were then:
- range (based on 80% charge)
- locakable if I have to leave the bike in town
- frame fixings and case part of the package
- low impact on the overall form factor of the bike when folded
Others will surely have different requirements and I really hope we get to see different builds coming out and see how they get on. Especially some more powerful rear hub designs...

Paradad · Nov 10, 2019

I do like the look of that softpack @wheeliepete !

Kwozzymodo · Nov 17, 2019

I am going to try and build a ‘Brompton Kit’ in the next few weeks. I think you need the Q70 front wheel motor as a starting point, as the fork widths on my folders are <80mm. I’ll report back with pics once The Project is complete.

Paradad · Nov 30, 2019

So my Q70 arrived this week. The details provided by BMSBattery have been ever so slightly less than useful!

Does anyone have a colour coded wiring diagram? It's even possible the wiring is the same as others "Q" series motors I guess. Any thoughts anyone?

Brompton Cute Q70 question

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