E-Brompton - First Ride/Tweaks

[jerrysimon]

This post is part of a set of posts following my project to "E" my Brompton :

A. Wheel Building - Tongxin in Brompton wheel

B. Building a small A123 Battery Pack

C. E-Brompton First Ride/Tweaks

D. Taking a Tongxin motor apart

You may also like to check out daniel.weck's post here which covers the simlar use of Tongxin & Bafang motors and inpired me to give this a go.

A couple of related links as I was building

Throttle Controls

Connectors


Well this afternoon after nearly 10 weeks of patience, waiting and building I test rode my new E-Brompton.

Its been quite a project, involving many highs and lows incl waiting for motors to arrive from China (which initially I thought were wrong and would not work), waiting for other electrical parts including making up my own battery pack from A123 cells and learning how to build and lace a wheel myself!

Intially I have just strapped the controller between the handle bars with some cable ties and put the battery and all the trailing wires in the Brompton C front bag . I have quite a few ideas for fitting different connectors, better positioning of the controller (probably in the bag with a single plug for throttle, motor and maybe a cutout brake) and some form of cutout/off switch. I also want a better connector for the battery. Its all a bit messy and loads to sort out, but fine for the test ride.

Anyway its always a buzz when you first test ride your new bike and this one certainly didn't disappoint. Intially I took it round the block holding my breath wondering if my wheel build would hold out, the batteries would work or the whole thing would crash and burn. I pedalled off and then pushed the throttle but not much happened, then I felt it start to kick in slowly at about 50% throttle. The throttle seemed very slow at first but this throttle seems to have all the control at the last bit of push. At 80% throttle it really picks up as you then go to 100% throttle. I was surprised at the grunt at this point as it gets very zippy. I am going to ditch this throttle and get a plain one without the battery indicator lights. At the moment the throttle is also on the right side and I am not sure if I like it there. I am also not sure if I will fit one of the brake cutouts, but that means drilling out the rivet to remove one of the Brompton standard brakes.

The decision to go for the slightly higher voltage of 12 rather than 10 * A123 cells seems the right one, though I have no idea how many amps I am pulling. I also still need to fit the 15 amp fuse.

I then went out for a few miles round the block before it got dark and I am very pleased. As I said its involved ten weeks plus of patience and methodically working through it all. Its been a real adventure though. At least having not gone down a pre built kit route, I know how it all works and fits together should I need to do any maintenance/repair. I also have a spare motor, controller etc to boot

I will probably order another rim in a few weeks when they are in and build another wheel as a spare.

Finally I just wanted to thank the many members here on the forum who have encouraged me and responded to my threads with advice and suggestions. Also I would like to thank Dan (daniel.weck) for all the emails we have exchanged, as he helped me with lots of questions and supported me through the project.

More later.

Regards

Jerry

 

[barrycoll]

CONGRATULATIONS Jerry...

as an EWC e Brompton owner, I have been following your build with bated (baited??) breath...

and its really great to hear that you have overcome all the difficulties, and now have a 'semi' finished product...
please keep us informed on what you do with the thumb throttle and the controller, as you too have noticed the 'last one third' effect of the present throttle...
and EWC also fit the controller between the bar uprights, which works, but isnt too aesthetic, although it doesnt call for any more connectors...

keep up the good work...

all the best barry c.

 

[NRG]

Great job Jerry, it looks superb! Enjoy the heck out of it

 

[flecc]

this throttle seems to have all the control at the last bit of push. At 80% throttle it really picks up as you
then go to 100% throttle.

Nice job Jerry, there's no better satisfaction than a home build.

Hall effect throttles, that's what probably is, all have similarly fierce characteristics, the "change-over" between
the magnetic fields cannot be much different whether it's a single or two magnet type. A resistance throttle can
be devised and will be much more progressive in action, but the potentiometer that it will normally be based on
hasn't the same reliability or safety. Probably why manufacturers don't use them.
.

 

[jerrysimon]

Thanks for the comments guys.

Tomorrow I am tied up with family all day, so probably won't get another ride till Thursday.

I am sure I will report then

Regards

Jerry

 

[Herb]

So few days but so much progress,

So many posts.

To build the battery and the wheel is fantastic.

Tell me, does the Turnigy charge the battery or is it just used to balance at the end.

Herb

 

[jerrysimon]

Tell me, does the Turnigy charge the battery or is it just used to balance at the end.

Thanks Herb. The Turnigy is a charger used mostly in the RC model enviroment and in fact charges many different types of cells. It requires a 12v supply though. It both balances and charges, though it may be that you don't need one for these cells if they don't go out of balance. In that case you can just use a cheap ebay charger like the one I purchased. We will see.


Regards

Jerry

 

[daniel.weck]

Fantastic news Jerry ! I hope you get many hours of trouble-free riding in reward for all your efforts, and well done for persevering despite the encountered impediments ! I'm glad you're going to ditch the bulky handlebar grip throttle...get something small and discrete, it works just as well (hint: black thumb throttle ) I wonder if the uneven acceleration/power curve comes from the controller rather than the throttle...I haven't tried my Tongxin loaded yet (i.e. running with the weight of the bike + rider), so I can't comment. Given your DIY skills and attention to detail, I'm sure you will find a neat solution for tidying these cables. It's nice to see a lightweight e-Brompton, unlike mine which is kind of a workhorse !! Regards, and congratulations again.

 

[trepo]

Great to see that you have got your electrified Brompton running! Your and Daniel Weck's threads have been a great inspiration source, thanks a lot.

I also have a 2009 M6L waiting for next summer and I'm going to install Tongxin motor into it... could you please PM me contact details of the Chinese kit supplier you used?

I live in Finland and it's not reasonable to use such a small-wheeled bike in winter time here. I have another self-built ebike for winter use with big 28" studded Schwalbe Marathon Winter tyres, here is a short youtube video of it:
YouTube - my 250W electric bike

That bike has SLA batteries, but probably i will buy a 36V10Ah Ping battery so I can use it on both bikes easily.

 

[eddieo]

trepo, loved the video. tyres seem to work well and your battery placement solution is excellent. if only all kits/home builds should look so good

 

[Barnowl]

Well done Jerry - I'm kind of wondering which bike is going to be your e-bike of choice during the coming months.

 

[jerrysimon]

I also have a 2009 M6L waiting for next summer and I'm going to install Tongxin motor into it... could you please PM me contact details of the Chinese kit supplier you used?

Done sorry for the delay.

Regards

Jerry

 

[emissions-free]

Good job Jerry, you've done really well.

I've bought an Icharger 208B, also an RC type balance charger. Also got some of the Cell Log8S monitors to monitor and log what is happening with the cells during use. They're nice bits of kit but they do they do get a little expensive by the time you've added it all up. I'll have to look into a cheaper balance charger and would be great if i could get something that will do more than 6 or 8 series cells. Ideally somthing that could do 16 or 20 LiFePO4 cells would be great if you know of anything that will do that.

 

[jerrysimon]

Ok a little update. Been out on a few more rides and everything seems to be working well. Its so cold out though!

I am now convinced that I want controller and battery in the bag and not mounted on the bike. I can fit controller and battery in one pouch but its easier to get to and better split between two. I tried using a few Speakon connectors but they are just too big, so at the moment I am still using Deans connectors. I am probably going to use a Souriau connector for motor and throttle connections into the bag. I need a minimum of 6 poles. These are used on the Cytronex.

I have now fitted a 15amp fuse in line (I may try a 10amp) and have been experimenting with a cutoff switch. Temporily its loose so I can find the best position. I will probably install it permantly on the right of left hand pouch near the top as I can reach this when riding. It works well and stops the sparking when connecting the Deans connectors together. Also being able to just reach over and isolate everything gives me assurance, should I need to do it in a hurry

Regards

Jerry

 

[daniel.weck]

Nice little switch. Which one exactly did you purchase from Maplin ? Oh, and is it spliced onto the red wire straight out of the battery, right after the blade fuse ? Cheers, Dan

 

[jerrysimon]

Dan,

10 amp Maplin Toggle Switch with a water proof cover.

At the moment its connected into the ciruit (on the positive red wire) using Deans connectors before the cable that goes into the controller but forward of the battery and blade fuse yes.

I will do another picture later.

Regards

Jerry

 

[jerrysimon]

I am still hunting around for a means of connecting the various wires from the bike to the controller. I need a minimum of 6 but ideally 8 poles if I want to use the emergency cut out as well.

So far I have considered Neutrik Speakon Connectors. I looked at 4 pole ones using two, but really I want a single connection and that means using the 8 pole one which is really quite big.

Also came across this which looks promising. Same brand as Freedom E's but smaller and round.

Maplin also sell them of a type

Although only rated at 6 amps/pin in this application I am pretty sure its more than enough. The wires/bullet connectors coming out brushless motor are pretty thin I doubt they could carry more than 3 or 4 amps.

The alternative is to use the Souriau as mentioned.

Regards

Jerry

 

[Herb]

Just a thought- If it was possible to fit the controller to the bike rather than the bag you only need a 2 pin connector to the battery - the motor and throttle connections etc. remain connected all the time.

If I ever change the controller on my Brompton I would like to mount it between the threaded mount on the stem and the plastic luggage block.

Herb

 

[Herb]

Another thought – If you use Anderson Power Poles, you can combine the modules in any rectangular configuration and easily make up a multi plug and socket arrangement
The power poles are rated at 30A

Herb

 

[jerrysimon]

Thanks Herb,

I really want the controller in the bag.

I did look at the Anderson Power Poles but have decided I am either going to use the Neutrik 8 pole or that Bulgin I have seen on ebay.

Having checked the Bulgin in Maplin my feeling is that the Neutrik will survive more connection cycles.

Regards

Jerry