Powabyke loss of power solved ??

[russell]

Thank you so much for the very quick reply...The problem I have is that earlier on this year I noticed that the wire coming from the hub into a connecting block looked very oddgy so I decided to tidy it up and make it waterproof, unfortunately I wasn't as careful as I should have been when connecting the 2 wires back up into a waterproof box and as a result when I switched back on it shorted out, I looked at the wiring again and decovered my clumsy fix had allowed the 2 wires to touch. I sorted that out but now when I turn the power key on the hub turns at full throttle without touching the throttle....I emailed Frank at Powabyke who advised that I had shorted the controller out somewhere and that I would need a new controller at £65 and a new throttle,,,cant remember how much..silly old fool that I am,,,I love my old Powabyke and rely on it to help me get a liitle exersize in my old age. It is a brushless motor

sorry my friends I have mislead you , I believe it is a brushed motor

 

[russell]

Hi russell
In your last posting you say you have a Brushless motor

Frank

Hello Frank,,I do apologise for the mistake, it is as you say a brushed motor.
I am overcome with your very very kind offer of the controller and throttle, it really is so generous of you.
neptune posted a little concern over difference in rating. Would you happen know what would be the worst thing that could happen if the controller is of a higher rating and would it be possible to give me some idea on connecting it up,,sorry to be a moning old sod but I am not so confident these days.

 

[banbury frank]

Hi Russel


Larger amps wont do any harm smaller amps would be a problem of burning out The Controller

the Physical dimensions are 95 mm long x 65 mm wide X 40 mm high + Cables

yes i can help with connecting up email me the connections on the old controller

Frank

 

[neptune]

The controller Frank is offering will do the job fine . It is rated at a max of 32 Amps , but your motor will not pull more than 20 amps , indeed it can not because your battery fuse is 20 amps.
The only worst case scenario is if you do something silly like connecting the battery leads wrong way round . That would blow the battery fuse , and probably the new controller. Also take note of the information that Stimil has sent you, as that way you have a plan B. Never be afraid to ask , on this forum we love to help fellow Ebikers.

OOps, Frank beat me to the reply!

 

[russell]

Hi Russel


Larger amps wont do any harm smaller amps would be a problem of burning out The Controller

the Physical dimensions are 95 mm long x 65 mm wide X 40 mm high + Cables

yes i can help with connecting up email me the connections on the old controller

Frank

That sound wonderful Frank,, I will with pleasure send you my email address and home address and will look forward to receiving the controller and throttle,, I can't express enough my gratitude to all of you fine people,,it really does restore my faith in human nature through these very difficult times,,,god bless you all....ps would it be any help to send you a picture of the connections Frank as I think there may be one on the Powabyke website,,,I will put it all together tomorrow and email you the details,,, it's about my bed time now and my heads buzzing,,,,,,,kind regards Russell

 

[stemil]

Could I just add a note of caution, I enquired on this forum about motor controller suitability for my Powabyke, I was thinking about buying a massively overrated controller on the premise (so I thought at the time) that the motor would only draw as much power as it needed and being under stressed it would more than likely last longer also, a good plan you might think?
This is the reply from D8VEH-

Just to re-inforce what NRG said: You can't use a controller that's rated higher than your battery and motor. It will try to draw too much current from the battery, which will cause it to cut-out. If you uprate the battery to be able to provide the current, then it'll try and push the maximum current that it's rated for through the motor, which will cause the motor to get hot and eventually burn. The three components need to be matched. Generally, 200/250w motors can take a maximum of 20amps if you don't use full power for too long. A 10aH lithium battery can only give 10 amps continuously and perhaps 20 amps for a very short time. Any more than 20 amps and the BMS will cut the power. SLA batteries can give a bit more for a short time and Lipos can give a lot more. 800w at v36v equals about 25 amps from the battery - just about possible from good 15aH SLAs, but you'd need at least 15aH lithium batteries.

The whole thread can be seen here-

http://www.pedelecs.co.uk/forum/electric-bicycles/10644-powabyke-motor-controller-suitability.html

I am not an expert on this subject and other than consult those who are far more knowledgable than myself I do not have a clue who is right or wrong. But, surely a 32 AMP controller, apart from the physical size and the problems that are likely to occur even mounting it, is capable of pushing out 1150 + Watts.
So hence my note of caution.

 

[NRG]

Correct!

 

[russell]

I have replaced the motor controller on a Powabyke Euro, you really need to use a unit of the correct rating, ie 36v 250 watts, I used this one- ebay item 220875379732 which works great.
Unfortunately a std Powabyke throttle does not work with this unit, but ebay item 320795877868 does, the only downside being that the wires have to be extended as they are a bit on the short side, I used the original Powabyke throttle wire cut off long enough to rejoin if required. The wire colours on the new throttle match the colour on the new controller, which is handy.
Connecting everything up can be made much easier with ebay item 170711501780, 3.9mm bullet connectors as they go straight on the connectors fitted to the motor controller.
You will need to solder double wires from the motor and neg terminal to single connectors though, I also did not use the brake cut off switch as my bike did not have provision for it and I can't remember if you join the wires or not to get the controller to work, but it's one of the two and all fairly straightforward.
The total cost being about 20 quid.
I hope this saves you some grief.

Well chaps,, I am between a rock and a hard place and don't know which way to turn..To try the very generous offer from Frank or go for the Chinese controller and throttle. After reading the latest post's about using a higher rated controller I am scared stiff in case it burns anything out, I am just not in a position financially to replace origional parts or buy a new bike. I would hate being without my old Powabyke.....As far as the Chinese parts are concerned,,, the wiring up sound a little confusing,, particularly the part about soldering up double wires from the hub as there are only 2 wires coming out, could you possibly help me out to understand...I am happy to try anything to get me back on the road..
thank you

 

[neptune]

There is obviously a bit of confusion, and difference of opinion here. We need to agree on this , to help the guy get his bike back on the road. I have some background in practical and theoretical electronics, but I am open to correction, and I do not know everything. When we talk about a 35 amp controller, what exactly do we mean? Do we mean that the controller will shut itself down when we try to put more than 35 amps through it?.
As I understand it, a controller works by pulse width modulation. So it is basically a switch, which switches the motor on and off at a very rapid rate. At a low throttle setting, the switch spends more time off than on . As we open the throttle more, the "on" pulses get longer than the off ones. Finally, at full throttle, the motor is switched on at all times, and there are no off pulses.
So at full throttle, the controller plays little part in the circuit, apart from acting as a closed switch. So at this point, the current draw is determined only by the battery voltage , the motor resistance, the motor back EMF, and any resistance in the battery and wiring. So at this point we could replace the controller with a bit of wire, with no damage to the battery or motor except that the motor would run at full speed all the time .
So if I am right [and please tell me if I am wrong] You could fit a controller rated at 1000 amps and it would work without damaging motor or battery.
REMEMBER THAT IT IS IMPOSSIBLE TO DRAW MORE THAN 20 AMPS FROM THE BATTERY AS IT HAS A 20 AMP FUSE.
That is my opinion, but we desperately need other opinions.
One way out would be to do exactly what Stimil has done, as his bike seems to be working without any problems.

 

[banbury frank]

Hi you a right you can replace the controller with a on off switch it is a standard 36 volt brushed DC motor so on off full speed

Frank

 

[NRG]

Yes, like the brushless types speed control is achieved using PWM. At full speed = full battery voltage where the BEMF the motor produces = the applied voltage so the motor cant spin any faster. At full speed current draw is minimum. As Torque is proportional to current it is also minimum. Now assume you hit a hill, the motor slows but the voltage applied is still = battery voltage, to compensate the motor draws more current to increase torque so it can maintain speed...slow the motor more and even more torque is needed so current rises even higher.

This cant continue, you have to limit the current to some point as the motor is only designed to produce so much power, they are greedy little whotsits and if you don't limit what they consume they will take too much, overheat, burn out or fail mechanically...thats why you need to limit the current to the motor...brushed or brushless.

D.C. Motor Torque/Speed Curve Tutorial:::Understanding Motor Characteristics

 

[neptune]

@NRG. Thanks for that explanation. This is more or less what I expected. So to return to practical matters. We do not know what the current limiter is set to in the original controller. Please tell me if you agree with the following three statements.

1. As the battery fuse is rated at 20 amps, the original controller will probably be 15 to 18 amps, so that working the motor hard will not blow the fuse, only an electrical fault will blow it.

2. If we fit a controller rated as say 30 amps, we will have no problem unless we work the motor really hard . If we do, the fuse will blow.


3.So basically what I am saying is that the ideal controller for this bike would be rated at 36 volts, 15 to 18 amps , which is equal to 440 watts.

Look on Ebay for 36v 250-350 W Speed Controller Box Electric Bike Scooter. Seller is novaproductsuk.
Same seller has also a throttle , check all dimensions. Controller is limited to 18 amps which is near enough.Wiring up looks straightforward.

 

[banbury frank]

Hi Russell Hear is the links for the parts Neptune recomended

36v 250-350W Speed Controller Box Electric Bike Scooter | eBay


eBay - The UK's Online Marketplace

Frank

 

[russell]

Hi Russell Hear is the links for the parts Neptune recomended

36v 250-350W Speed Controller Box Electric Bike Scooter | eBay


eBay - The UK's Online Marketplace

Frank

Well, what can I say,,,I am flabbergasted that you lovely people I have never met could be so very helpful..This forum is a wonderful example of why the older generation should embrace the Internet, they would soon recognise as I have that although many things that go on in our society make us all nervous and sometimes uncomfortable, there are always hundreds of good people out there who are prepared to give their own time up simply to help people...Thank you all.
I am going to go for the controller and throttle that neptune recommends but would feel less nervous if I could possibly post another question if I have problems wiring it up.
If you feel you have all helped enough I will understand,,,,I will let you know how I get on,,,,regards Russell

 

[russell]

Well, what can I say,,,I am flabbergasted that you lovely people I have never met could be so very helpful..This forum is a wonderful example of why the older generation should embrace the Internet, they would soon recognise as I have that although many things that go on in our society make us all nervous and sometimes uncomfortable, there are always hundreds of good people out there who are prepared to give their own time up simply to help people...Thank you all.
I am going to go for the controller and throttle that neptune recommends but would feel less nervous if I could possibly post another question if I have problems wiring it up.
If you feel you have all helped enough I will understand,,,,I will let you know how I get on,,,,regards Russell

Just looking at the picture of the controller,,,the original controller doesn't have any plugs on it just plug in sockets, I am a little confused or probably just stupid,,,,

 

[neptune]

Hi Russell. This is what I meant when I said in an earlier post that a sustitute controller may not be "plug and play". Bear in mind that I although I have worked in electronics, I have never actually seen one of these controllers, and although I run a Euro, I have had no cause to get the controller out. If you look at the picture of the controller, it has connectors on the ends of the wires. It is hard to tell from the photo, but some of these connectors may be female, or sockets. Equally, they may not be. In that case you will have to remove at least some of these connectors, and replace them with connectors that are compatible with the connectors on the wiring of the bike. If such can not be found , you will have to change the connectors on the bike wiring as well. Note that this controller does not have a pedalec option. Nor does it have a connection for the motion sensor fitted to the rear wheel of your bike, if it is a pre 2002 model . The only down side of this, is that if you switch on the ignition, the bike will pull away from a standstill as soon as you open the throttle. This is bad for the motor and battery, so the way to ride it will be to pedal up to about 4MPH before opening the throttle.
Some of the wires on the controller can remain unused, like the brake cutouts, and the charger wires because you already have a charge socket on your battery . The wires you will have to connect are as follows.
2 motor wires.
2 battery wires.
3 throttle wires.
2 Ignition switch wires.
and if required, 2 wires for the battery level indicator .
So you are looking at changing some connectors and doing some soldering. There are several types of connector that will serve, including automotive bullet connectors, and automotive blade connectors. It is important that you understand what is involved before you commit yourself. It is a shame you don`t live nearer to me. Do not pull any wire off your old controller without carefully making a diagram. If you decide to go ahead, I will give you my phone number via private message . Remove battery from bike before doing any work at all .

 

[Davanti]

..This forum is a wonderful example of why the older generation should embrace the Internet ...regards Russell

Hi Russell. Pleased you have found those lovely people on this Forum to help. Sorry that I've not been sufficiently knowledgeable ... or old enough ... to contribute ... I'm only 71 (or is it 72?)

Don

 

[russell]

Hi Russell. This is what I meant when I said in an earlier post that a sustitute controller may not be "plug and play". Bear in mind that I although I have worked in electronics, I have never actually seen one of these controllers, and although I run a Euro, I have had no cause to get the controller out. If you look at the picture of the controller, it has connectors on the ends of the wires. It is hard to tell from the photo, but some of these connectors may be female, or sockets. Equally, they may not be. In that case you will have to remove at least some of these connectors, and replace them with connectors that are compatible with the connectors on the wiring of the bike. If such can not be found , you will have to change the connectors on the bike wiring as well. Note that this controller does not have a pedalec option. Nor does it have a connection for the motion sensor fitted to the rear wheel of your bike, if it is a pre 2002 model . The only down side of this, is that if you switch on the ignition, the bike will pull away from a standstill as soon as you open the throttle. This is bad for the motor and battery, so the way to ride it will be to pedal up to about 4MPH before opening the throttle.
Some of the wires on the controller can remain unused, like the brake cutouts, and the charger wires because you already have a charge socket on your battery . The wires you will have to connect are as follows.
2 motor wires.
2 battery wires.
3 throttle wires.
2 Ignition switch wires.
and if required, 2 wires for the battery level indicator .
So you are looking at changing some connectors and doing some soldering. There are several types of connector that will serve, including automotive bullet connectors, and automotive blade connectors. It is important that you understand what is involved before you commit yourself. It is a shame you don`t live nearer to me. Do not pull any wire off your old controller without carefully making a diagram. If you decide to go ahead, I will give you my phone number via private message . Remove battery from bike before doing any work at all .

Thank you for the guidance,,,it doesn't sound too bad, I will order the parts and go for it, first I will take out the controller and try to familiarise myself with what each socket is for and the colour of the wires going into each socket from the bike,, I will also take pictures of each step of the way to refresh my memory,,,fingers crossed,,,I dont know whereabouts in the country you are but if you were nearby I would have the greatest pleasure in treating you to a pint. I promise to let you know how I get on

regards Russell

 

[russell]

Thank you for the guidance,,,it doesn't sound too bad, I will order the parts and go for it, first I will take out the controller and try to familiarise myself with what each socket is for and the colour of the wires going into each socket from the bike,, I will also take pictures of each step of the way to refresh my memory,,,fingers crossed,,,I dont know whereabouts in the country you are but if you were nearby I would have the greatest pleasure in treating you to a pint. I promise to let you know how I get on

regards Russell

I have just had a look on the Powabyke web site and found the wiring connections they read
7 pin power
pedal/motion sensor 3 pin
ignition 3 pin
throttle 3 pin will this cause me problems with the replacement, I promise I wont bother you again (at least not tonight)

 

[stemil]

As far as the Chinese parts are concerned,,, the wiring up sound a little confusing,, particularly the part about soldering up double wires from the hub as there are only 2 wires coming out, could you possibly help me out to understand...I am happy to try anything to get me back on the road..
thank you

Hi Russell, The Motor cable doubles up above the connector located on the left fork, I do not have the bike to hand at the moment but going from memory red and blue = positive, yellow and green = negative.
Roughly where are you located?
Good luck.