Just received a Bafang SWXH 36v, 250w.

[Trout]

First of all,

Hi everybody, this is my first post.
I've been lurking around this forum for quite a while and reading other threads. There is alot of helpful information posted by people here.

I decided to go for a Bafang (8fun) qswxh motor and an aluminium alloy 12aH, 36v battery. And i got it from BMSbattery.
The S&H was damn expensive (1/3 of total price) but i got it in 8-9 days.

The thing is that they forgot to send the set of keys to the battery! and now they have their chinese new year holiday or whatever it is.

I dont actually need them right now as i dont ride the bike during the winter (living in Norway) but i need them. I had to open up the battery and solder a cable to the back of the ignition thing . (to complete the circuit). And the battery outputs 39.9V.

Had some troubles setting up the cables from the ESC to the motor but finally i managed to get the motor running.

I intend to make this ebike Eu-legal, and i have a pedal sensor (but currently not connected as i'm just testing/messing around with the kit)

I have some questions though...

#1 Can i charge the battery as normal with the circuit i've made?

#2 I dont really understand those "Phase" cables. I have phase a, phase b, phase c... currently i have all of those connected and the motor runs... Should i use just 1 phase?

#3 Follow up question to the previous one, the 5 "motor hall sensor wires", should all of them be connected? (Red :5V; Black:GND; Yellow:Hall phase A;Green:Hall phase B;Blue&White: hall phase C)

I'll try to post some photos if anyone is interested.

Thanks

 

[z0mb13e]

Hi Trout,

Can you charge the battery with it 'switched on'? I would think so. I have charged my Whisper battery with the key in the on position (though not connected to the bike) and it charged ok.

The phase cables supply different windings in the motor and yes, they should all be connected. The phases refer to the angular positioning of the windings.

All the hall sensors should be connected. They are active devices and so need power and ground and the other wires provide information on the angular position of the motor. The controller in combination with the information from the hall sensors provides power to the various phases of the motor in sequence. I have read of motors and/or controllers that use a single hall effect sensor but I have never seen one myself...

 

[JuicyBike]

Hi Trout and welcome.
I'm sure someone will be along shortly who can answer all your questions.

For the time being, you do have a controller in your system right? This will connect to the hall sensors in the motor and so regulate the speed of the motor.

What controller are you using?

 

[flecc]

Best practice is to have the system switched off when connecting and switching on a charger, since this avoids connecting any pulse currents which might damage the controller or a Hall sensor in the motor.
.

 

[Deleted member 4366]

Whether you connect the hall sensor wires or not normally depends on the controller. I believe that the BMS controllers can work with or without them connected. and there is a self-learning procedure within the controller, where it figures out whether they're connected or not. If you have this controller,best would be to connect them and do the self-learning, and then in the future, if any of the sensors fail, disconnected them and do the self-learning procedure again. Then you won't need them. AHaving said that, with your motor, it probably won't make much difference whether they're connected or not, so, if you're happy as it is, just keep it like that.

Charging the battery with your modified wiring should be OK, but depends where the charger wires feed in. When you switch on the charger (not connected to the battery) the LED should be green. If it turns red when you connect it to the battery, everything is ok and it's charging. When the battery is fully charged it'll go back to green again.

 

[Trout]

Thanks for all the answers guys!

Hi Trout,

Can you charge the battery with it 'switched on'? I would think so. I have charged my Whisper battery with the key in the on position (though not connected to the bike) and it charged ok.

The circuit i've made is as if it was to "switched on". That was what i was wondering. because i see that the battery has a "charge setting" in the "key ignition". Thanks

For the time being, you do have a controller in your system right? This will connect to the hall sensors in the motor and so regulate the speed of the motor.

What controller are you using?

Its the bms controller "KU63 - 6Mosfet". I guess its 36v/250w

Whether you connect the hall sensor wires or not normally depends on the controller. I believe that the BMS controllers can work with or without them connected. and there is a self-learning procedure within the controller, where it figures out whether they're connected or not. If you have this controller,best would be to connect them and do the self-learning, and then in the future, if any of the sensors fail, disconnected them and do the self-learning procedure again. Then you won't need them. AHaving said that, with your motor, it probably won't make much difference whether they're connected or not, so, if you're happy as it is, just keep it like that.

Charging the battery with your modified wiring should be OK, but depends where the charger wires feed in. When you switch on the charger (not connected to the battery) the LED should be green. If it turns red when you connect it to the battery, everything is ok and it's charging. When the battery is fully charged it'll go back to green again.

Didnt know about that self-learning feature.. I guess bmsbattery/ecitypower are not known for their documentation...



I've having some trouble with the thumb throttle though..
its this kind:

It has 6 wires:

three of the cables are soldered to a connector that connects to the controller for the throttle
Red --- +5V, Black --- GND, White --- Signal. (works fine)

two of the cables are soldered together for some reason.
Yellow --- Brown: Round Red Switch.

and the last cable is:
Green: Battery(+) for Battery Meter LED Display.

i've figured out that when i press the red button it completes the circuit between Yellow+Brown and Green


this is the instruction for the power input of the cotroller:

Power wire (3P Plug)
Red ower Anodic; Black:Cathodal; Orange(small wire): power key on/off lock
Connect Red to Orange(small wire): power on.
Disconnect Red to Orange(small wire): power off.

So the obvious way to set it up (according to me) would be to connect the connector from the throttle to the connector on the controller (that works fine).

and connect Green to the Red(positive) on the power input of the controller.
and connect the yellow+brown to the Orange cable of the power input of the controller.


The thing is.. throttle works.. red power on/off button works.. but the LEDs of the throttle dont work.. well all the LEDs are turned on.. Full, Half, Empty.. instead of just one being on..

What am i doing wrong?

 

[banbury frank]

Hi

forget the lights they only work on lead acid battery's

Frank

 

[Trout]

Hi

forget the lights they only work on lead acid battery's

Frank

Haha ok! Actually it doesn't even surprise me.

 

[aseb]

Hi

forget the lights they only work on lead acid battery's

Frank

The leds should work on different types of battery chemistry but the points at which they say fully charged, half charged, flat will be different so they will light differently when using other chemistries to a lead battery (fully charged voltage is different for different chemistries, as is 'flat'- for example my throttle led cuts out shortly after the middle level led operates using my LiFePO4 but shows the expected behavior when using the original batteries supplied with the bike).
Either the wiring isn't correct, or it doesn't work. And it may not give you an accurate indication of the state of your battery charge anyway. So you might find it of limited use if you get it working anyway. Mine changes to the second light when I have less than a mile left so isn't much use apart from telling me I'll have to use pedal power alone very soon.
There are other meters you can fit, from led voltmeters that will tell you what voltage the battery is at (you'll soon get a feel for what voltage is fully charged, battery cuts out etc), there are ebay sellers who have led meter and at least one will customise the voltage points that trigger leds to your specifications.
Then there are the meters like GT Power Watt meter or WattsUp, that will measure the actual current being consumed as well as the Voltage. Or the best of the lot- the Cycle Analyst at around £100.

 

[Deleted member 4366]

The extra three wires on the throttle: two for the switch and one for the LEDs. If I remember correctly, the two joined together go to the positive 36v input to the controller and the other one goes to the orange wire from the controller that is probably joined to the main 36v positive feed. The orange wire switches the controller standby function on and off depending whether it's live. If you connect it directly to the thick red wire (36v +vv) into the controller, it'll be on when the battery is switched on. When you run the orange wire to the throttle switch and back to the 36v +ve, you can switch power from the controller on and off without having to switch off the battery - much better solution. I think that's what you've figured out

When the LED wire is connected to the 36v +ve, all the LEDs come on. When power is used up and the battery starts to go flat, first the green one goes out, then the orange as well, leaving the red on it's own to warn you to start your breathing exercises.

You can get a PDF document that explains the wiring from ecitypower.com under "downloads"

 

[Beano]

A mate of mine bought a kit from bmsbattery but when it arrived the controller was missing. They refused to send one out unless he paid for the shipping....nearly £70.
Hope you have better luck Trout.
Regards... G

 

[banbury frank]

Hi you have in there a + feed straight off the battery you need to fuse it somewhere or you will have a fire in the wiring

Frank

 

[Trout]

Then there are the meters like GT Power Watt meter or WattsUp, that will measure the actual current being consumed as well as the Voltage. Or the best of the lot- the Cycle Analyst at around £100.

That cycle analyst is really ridicoulsly expensive. I do some RC as well. those watt meters by turnigy or hobbyking cost like $20. I agree that cycle analyst have some functions that the other ones dont have. but hey, its the same hardware.

When the LED wire is connected to the 36v +ve, all the LEDs come on. When power is used up and the battery starts to go flat, first the green one goes out, then the orange as well, leaving the red on it's own to warn you to start your breathing exercises.

I guess i did set it up correctly. it just looked so weird with all the LEDs being turned on. Thanks

A mate of mine bought a kit from bmsbattery but when it arrived the controller was missing. They refused to send one out unless he paid for the shipping....nearly £70.
Hope you have better luck Trout.
Regards... G

I've been mailing back and forth with them. They say that they had 3 different persons checking the parcel so that it contained all the stuff i ordered. They refuse to send me a set of keys. F*kk em.

The lock on that battery didnt look very sofisticated so i just tested some keys i had laying around at home and found a set that works with the battery! well.. I can easily turn it On / Off but i cant "unlock" it.. to remove it from the "cradle". I've been studying the lock and it might be that my key is a bit too short...

I assumed that the keys were custom to every lock. but i think its just 1 set of keys for all the locks.


If anyone could take a picture of their key side by side of a mm-ruler i would appreciate it alot!!

 

[jbond]

That cycle analyst is really ridicoulsly expensive. I do some RC as well. those watt meters by turnigy or hobbyking cost like $20. I agree that cycle analyst have some functions that the other ones dont have. but hey, its the same hardware.

The one thing that the CA can do that the Turnigy or Wattsup can't is the current limit/speed limit. I'd love to see someone design a circuit to do this external to the controller. £20 for the Turnigy meter + £10 for a home build external current limiter would be way better than £130 for the CA. The CA is also a cycle computer, but a basic one is £15 from Halfords. Total is still under 1/2 of the CA price.

There are people messing with the Turnigy programming to make it do more stuff. But apparently it's very limited on RAM so the programs have to be very simple.

Thing is, it ought to be possible to duplicate the CA much cheaper as there's really not very much in it physically and most of it's cleverness is in the software. But it is available here now and finished as a commercial product. That makes it almost worth the money.

 

[Deleted member 4366]

Trout, to unlock the battery, sometimes you have to push the lock in and turn it at the same time. If the problem is the lock itself and you can at it to disassemble it, you could remove the barrel and take out the tumblers so that any key will turn it. Then reassemble it. It's easy to do - once you've removed the barrel, the tumblers just fall out. Only you'll know that, so it should still be safe unless you want to regularly leave it unattended in the same place.

 

[banbury frank]

with the CA the best feature that it has is the battery meter as far as I know the only accurate battery meter available it works by telling it the AH off the battery then it deducts the amount you have used

But as usual we have cries off to expensive

You get what you pay for this product linked to there Infineon controller

works out off the box and the support is second to none





Frank

 

[Beano]

Trout, to unlock the battery, sometimes you have to push the lock in and turn it at the same time. If the problem is the lock itself and you can at it to disassemble it, you could remove the barrel and take out the tumblers so that any key will turn it. Then reassemble it. It's easy to do - once you've removed the barrel, the tumblers just fall out. Only you'll know that, so it should still be safe unless you want to regularly leave it unattended in the same place.

Yes that's right about pushing the lock in to unlock those.
I'll see if my mates key is the same as mine. Maybe they are all the same.
Regards....... G

 

[Trout]

Trout, to unlock the battery, sometimes you have to push the lock in and turn it at the same time. If the problem is the lock itself and you can at it to disassemble it, you could remove the barrel and take out the tumblers so that any key will turn it. Then reassemble it. It's easy to do - once you've removed the barrel, the tumblers just fall out. Only you'll know that, so it should still be safe unless you want to regularly leave it unattended in the same place.

Great pointer! Thanks.


I took the bike for my first test ride today. quite a heavy wind and -18 celsius. Pff. I was just out for 10 minutes or so, couldnt stand more.

I tried quite a steep hill and experienced some weird behavior. Or maybe its not weird..? It was like pulses. Like 2-3 seconds of power and then maybe 0.5 sec of no power and then 2-3 sec of power and so on.. Almost like the motor was skipping or something.. This was at quite a slow speed. Anyone who has experienced this?

On flat and less-steepy-hills the motor ran smooth as butter. It was really pleasant to drive it.. It was a very short test ride but i got the feeling that the motor had more torque at about 50% of top speed than at slow speed.

This test ride was without the pas sensor. moped-style.

 

[Deleted member 4366]

A couple of possibilities: It's easy to accidentally open the throttle a little when pedalling, especially when pedalling hard up hills. The pedal sensor normally gives full power as soon as you pedal, but the throttle takes precedence at the controller, so if you open the throttle just a little bit, it cuts the power to just a little bit. Next possibility is that there's too much gap at the pedal sensor between the magnets and the pickup, or even that the magnet disk is slipping on the shaft. If it's the latter. you can fix it with a bit of hot-melt glue. For the former, you might want to think about a spacer between the pedal/chain-wheel and the disk or even more hot-melt glue.

 

[Trout]

A couple of possibilities: It's easy to accidentally open the throttle a little when pedalling, especially when pedalling hard up hills. The pedal sensor normally gives full power as soon as you pedal, but the throttle takes precedence at the controller, so if you open the throttle just a little bit, it cuts the power to just a little bit. Next possibility is that there's too much gap at the pedal sensor between the magnets and the pickup, or even that the magnet disk is slipping on the shaft. If it's the latter. you can fix it with a bit of hot-melt glue. For the former, you might want to think about a spacer between the pedal/chain-wheel and the disk or even more hot-melt glue.

No but my test ride was without pedal sensor. Only a thumb throttle, controller, motor, battery. And i'm certain i didnt open the throttle due to pedaling.
It was like a "skipping" feeling.


Maybe i'm just getting it wrong, bear with me. I just get the impression from what you write, that its either a pedal sensor that you use or a throttle.. I thought the pedal sensor worked as an On/Off switch, and the Throttle controls the speed. Isnt it? That you can use both of them if you want.