Improving speed on my 37V 250W bike

[cleanair]

Hi all,

first of all, I'm new to the forum and my electric/mechanic engineering skills are close to none. I hope somebody can help me!

About a couple of months ago, I bought a Raleigh 37V 250W e-bike at a local bike shop. For those in Canada, it's exactly the same as WalMart's 24V 250W Triumph (except for voltage).

I primarily purchased the bike to commute to work (about 18km each way).

Except for its weight and performance when pedal-only, I'm generally OK with the quality of the bike. However, due to work and family needs, I can't afford riding at 25KPH (top speed). :x

My understanding is that under ideal conditions a 36V system should allow me to go at about 40kph -please somebody correct me if I'm wrong. However, my bike's speed is limited by a pedelec system, which also requires 5kph for the motor to kick-in.

The battery is a Phylion 37V 10ah Lithim-ion 1C rating at nominal 9.5ah. So, I know that I have about 370W of power for an hour.

I'm wondering what my options are to substantially improve speed.

I guess migrating to a 48V system would be a good solution, which I'll eventually try. For now, I want to keep my configuration, particularly considering my battery is brand-new.

Thanks!

 

[steveo]

Hey

Higher voltage would be the best soloution. I'd recommend a 48v battery pack.. or add a 10ah lipo battery in series with your present battery to total 48 nominal voltage!

you battery is perty "garbage" excuse my language ...

i would at least think 20 amps!!! .. 10 amps ! gahh..

I run my bike at 132amps .. and i have day where i'm like thats it? not enough power lol..

oh yea.. if you need a controller i have some avaliable, just pm me

-steveo

 

[monster]

what type of motor do you have brushed (two wires) or brushless (8 wires)? if its brushed then you can just bypass the anoying PAS controller with a switch and add extra batteries for speed. increase the batteries slowly and monitor temperature to see if it gets hot.

if its brushless then you can try adding more batteries but you might have to buy a new controller. thats my understanding.

 

[Drunkskunk]

Welcome to the forum.

36 volts could give you 40kph, but its the same as saying 1 liter of gas could make your car go 200kph. It really depends on the motor.

To get 40kph out of your motor you're going to need more voltage, and probably a new controller. and its questionable if that motor will be able to maintain 40kph without cooking

 

[dogman dan]

250 watts is pretty weak, so the battery doesn't need to be much. upgrading the controller and batteries might help, most motors can take some more but doubling it would be dicey. Maybe you could sell the bike and start over with something more powerfull? Aotema front hub kits are pretty inexpensive but still pretty fast for the money.

 

[cleanair]

Thanks all!

Steveo, earlier yesterday I tried to PM you but for some reason my message didn't go through, do you know why? :?

In terms of migrating to 48V, that's definitely my ultimate goal. However, spending more money on my bike 2 months after buying it, would simply call for marriage trouble. That's why I need to find a temporary solution within a few-buck range and keep my current configuration as intact as possible. Dogman, I don't think selling my bike would be an alternative. I'm from the Canadian Prairies and there's just no local market for it; privately shipping out of town: impractical.

However, I'm certainly interested in knowing Steveo's suggestion of increasing 36 to 48 volts by adding an extra battery "in-series". As a mentioned before, I'm just a beginner... Could anybody please expand in plain english on how to do the "in-series" connection. As a future project, and provided my battery doesn't die before that, I'll likely take this road to increase to 48V, and then go for the 48V motor and controller.

For now, I believe that my immediate solution is to replace my current controller for one without speed limiter and pedelec. I browsed through e-Bay and saw those off (private) road, "brushless start immediate" controllers. Am I on the right track?

If so, I'm not sure about controller's amps. Having a 370W battery and 250W motor, I'm affraid of frying my little motor (Bafang 37V 250W brushless on a 28-in rim). Please give me your thoughts about the type of controller that I'd need to maximize speed, without burning my bike -please include as much detail as you wish, including specs and number of amps.

Thanks

 

[dogman dan]

Go read some basics in the tech reference section, or battery university for stuff like series and parallel connections. Yeah, a new controller would do the trick, but not all will work with the gearmotors, so get one from knuckles or somebody that sells controllers for bafangs. You should be able to get one in the 400-500 watt range that will go about 18 mph or faster. Amps x volts = watts, so your 36v controler must be only about 7 amps. Pretty weak. If you can find a bafang compatible controller in the 10-15 amp range, you should have decent speed without even going to higher voltage.

Correct me if I'm wrong guys, but shouldn't a bafang handle 500 watts with no problems? Mabye even 700? As far as I know the motor is the same for all the different wattages under 500 watts. I think a 36v 15 amp controller, or a 48v 10 amp would be no problem. You could have issues with the battery if you go too high amps though, since it is likely to be matched to the 250 watt rate of discharge. It should be able to handle a 10 amp controller, so adding a battery in series, and a 10 amp 48v controller could be a good way to go.

My fusin motor, very similar to a bafang, goes 20 mph easily on 36v. Its controller also has a speed limiter function, and when you connect the jumper you get speeds very similat to what you have. Look at the controller, and see if you have any single wires that come out, and connect to another single wire, and then go back to the controller. Maybe you can disconnect it and then have more amps, and all the speed you need.

 

[cleanair]

I checked my current controller, and you're right Dogman, it's a 7amp. I also check for single wires, but all I have are three(or more)-wire connectors. Regardless, I tried to disconnect one by one, and either I got no noticeable change, or dead motor.

I think I'll go for a controller replacement. Just need to find the right one for my 37V 250W (little) Bafang motor, which would allow me to top up its speed. Ideally, I should be able to find a 36V 10-15a controller for geared brushless motors, compatible with Bafang, and... no speed limiter, PAS or the like!

I appreciate list of websites that would ship to Canada

Thanks!

 

[www.evlogix.com]

If the controller is limiting the current at top speed (Which 7 amps could do it), getting a new controller with a higher current limit would boost your speed. Otherwise, increasing the voltage is the best route for a hub motor. You can keep your battery and just put another one in series to increase the voltage, it seems 12v SLAs are fairly popular for this. If your original battery is lithium, there are extra precautions to be taken to protect it if you decide to do that.

 

[kriskros]

I have the same notor.... i use an infineon 36v 20 amp controller on a ping v2 36v 12amp battery... the controller is wired for a cycle analyst direct plug in.... source,Comcycle usa...$79.00us they ship to canada... i am in ontario a very good controller

 

[OneWayTraffic]

It may be possible to simply modify the controller for higher speed. Pull it apart and take pictures of it. OR try to contact the manufacturer for details. I know that at least one other production bike for the UK market can have it's speed increased from 15mph to 19mph like this. It's as simple as connecting/disconnecting wires or turning a screw.

 

[cleanair]

I went for an Infineon 36V 20a. Once arrived and wired (if I'm able to do it ), I'll report results...

 

[cleanair]

After a long wait, I finally received the infineon controller... but couldn't make it work. The hall/motor connector coming from my Bafang motor has 4 wires (not 5 as in the controller). The wiring colours coming from my bike's motor are: red, black, yellow and green. This is, I'm missing the blue one. :?

The wiring diagrams per Knuckles or "Known to..." posts correctly show the different combinations of phase/motor and hall/motor wires, but always using the blue, green and yellow.

Tried to wired w/o blue one... but the thing is dead...

Help much appreciated.

 

[dnmun]

why is it 37V? is this a brushless motor? do you have any pictures of the motor or controller?
do you know what all the wires going into the controller do?

 

[cleanair]

37v is what's labelled on the motor, controller and battery. I haven't tested myself. My Bafang motor is brushless and looks like attached doc without the "8FUN" label -it appears to have been built specially for raleigh (or its chinese manufacturer).

My stock 36/48v 20a infineon controller's connectors look exactly like e-crazyman's, picture's attached.

With respect to the motor-controller wiring, it looks pretty clear to me: the three phase fat wires (blue, green & yellow), the brake wires (yellow & black), and the three throttle wires (green, red & black). The hall wires coming from the motor though are 4, not 5 to match the controller's. This is, the controller's hall (thin) wires are red, black, blue, yellow and green. The motor's conector has 4 thin wires: red, black, yellow and green. No blue thin wire from the motor.

In addition, there's another connector coming from the motor. This conector has 3 thin wires: red, black and green. Perhaps, this is the speed sensor -remember that my bike has a speed limiter by factory to 25km/h. My Bafang motor has a circular magnet screwed to its right side. The right arm of the fork has a sensor which looks like a small cylinder(similar to the speedometer's).

I plugged the controller without the blue thin wire (and obviously without the speed limiter connector) and nothing... I tried Knuckles' combination of G/Y and Y/G for both motor and phase, and also G/G and Y/Y, and again, nothing...

My bike has personality of his own, doesn't want to be changed... :?

 

[dontsendbubbamail]

This might be something to check. As I understand it, the logic power and the motor power are separate. To power up the logic side of the controller, I think you need to put power to that small red wire on the battery connector.

Bubba

 

[dnmun]

that bafang brochure says sensorless. do you have a picture of the motor?

 

[cleanair]

here're pics of my Bafang...

I thought the thin red wire on the connector from controller to battery was useless. I only connected the thick red and thick black. Maybe that's part of the problem. Please could anybody confirm.

Still, I don't know why there's a connector from the motor with red, black, yellow and green without the respective blue...

 

[The7]

The motor says "Brushless without Hall Sensor".

This means that there is no Hall Sensor in this motor. This is a pedal first type. The 4 control wires are for 3-phase emf detection using an extra 3-phase control windings.

The controller that you bought is not the correct type. You need a special controller for this special motor.

 

[docnjoj]

My rear Bafangs both have Halls and work fine!
otherDoc