Help! Problem with Voilamart controller

[Tonywilson123]

Hi all
i am new to the site but have had a Voilamart 36v 250w-750w front wheel conversion for about 6 months (although it was previously pre loved for who knows how long) and I suspect that I have controller issues. It has locked into 750w setting so I have no low power torque (+it is illegal). Can anyone tell me if I can wire it back to 250w or does anyone know where I can get a replacement controller from, photo of tag attached.

 

[Nealh]

Dual watt controllers are custom programmed so one needs to get one from the same vendor .

 

[Tonywilson123]

Dual watt controllers are custom programmed so one needs to get one from the same vendor .

Could I retro fit a new controller to my system

 

[Nealh]

Yes you would need a matching controller as well.
Your existing controller is 22 max so you can fit a 22a model to have the power of the current one. Most controllers only allow about 15a but if you buy a KT model and lcd3 for about £70 you can vary the current levels down if you buy a 22/25a controller and find the current to high. Kt make various controllers from 12a to 25a for most low power bikes. KT gives you five PAS levels.

You need to buy the right controller they are for either sensored hubs or unsensored, buy the correct type to save having problems.

 

[Tonywilson123]

Yes you would need a matching controller as well.
Your existing controller is 22 max so you can fit a 22a model to have the power of the current one. Most controllers only allow about 15a but if you buy a KT model and lcd3 for about £70 you can vary the current levels down if you buy a 22/25a controller and find the current to high. Kt make various controllers from 12a to 25a for most low power bikes. KT gives you five PAS levels.

You need to buy the right controller they are for either sensored hubs or unsensored, buy the correct type to save having problems.

Thanks for the info - l will Look at the bike in the morning and see what is what.

 

[Tonywilson123]

Thanks for the info - l will Look at the bike in the morning and see what is what.

Thanks for the info - l will Look at the bike in the morning and see what is what.

well I seem to be well and truly out of my comfort zone. Nothing seems to have the right connections - would it be simpler to change the whole wiring harness, I use the bike for short journeys so I don’t really want to spend a lot of money on a hit or miss purchase,

 

[Nealh]

If changing controllers from one make to another they aren't always plug and play.
The battery connections are basic Red to Red & Black to Black often bullets.
The three phase wires are also easy and likewise couloir to colour and bullets.
The white connector with 5 or 6 thinner wires is also a std hall connector and simply plug and play.
One doesn't have to worry about the display wiring because a new compatible matching one will need to be bought with the controller so it would simply plug in.
That only leaves two connections a throttle if used again a simple connection as is the PAS sensor connector. All one needs to do is simply match the wires correctly so some pics and we can tell you exactly what goes to what.

It might seem hard or tricky but is quite simple with our help/advice. Cost is about £70 - £100 for the decent friendly to use KT controller/lcd.
Sometimes a soldering iron comes in handy so it is best to have one at hand.

 

[Nealh]

We can show you where and what to buy.
It's unclear if you have a speed sensor, to tell look at the white connector block with the thin wires. If you have speed sensor inside the hub there will be a white wire on both parts of the connector if not look as the rear wheel to see if a spoke magnet is attached.

Are you happy buying via Chinese suppliers ?

 

[Nealh]

< £73.50 delivered.
KT 22a controller and lcd, perfect for your set up. Wiring should be easy to marry up.
This is for a sensored hub like yours, if 22a is too much current one can simply reduce it by making changes via the display.
Battery and phase have push fit bullets, the white sensor connector simply connects to your one from the hub motor (one just needs to check the colours match).

30.72￡ 8% OFF|Ebike Motor Kt Controller 500w 22a For 36v 500w 48v 500w 9 Mosfet Kt Sine Wave Controller + Kt Lcd3/lcd8h/lcd8s - Electric Bicycle Accessories - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

If one looks at the third thumb nail under the main pic you can see all the connectors fitted and there descriptive use.

 

[Tonywilson123]

We can show you where and what to buy.
It's unclear if you have a speed sensor, to tell look at the white connector block with the thin wires. If you have speed sensor inside the hub there will be a white wire on both parts of the connector if not look as the rear wheel to see if a spoke magnet is attached.

Are you happy buying via Chinese suppliers ?

Hi - thank you for your time, there is nothing on the rear wheel and no white cable on the white connector- photo attached - I also have a twist throttle (+thumb throttle that came with bike), I don’t mind Chinese if not too long a wait and I have a soldering iron At the ready.

 

[Nealh]

For the lcd speed reading one can buy a simply 3 wire speed sensor from the same supplier, attach the sensor to the rear stay and the magnet to the spoke.
The controller has a separate connector for the external speed sensor.

 

[scott gaza]

Changing your controller won't help as it looks like you have a direct drive hub that's probably wound for high speed Sorry

 

[Tonywilson123]

Changing your controller won't help as it looks like you have a direct drive hub that's probably wound for high speed Sorry
[/QUOTE

Changing your controller won't help as it looks like you have a direct drive hub that's probably wound for high speed Sorry

is that a polite way of saying “I am screwed”???

 

[scott gaza]

No im sure a 210rpm geared hub would be ok for your needs Just not 100% sure it would be a straight swap

 

[Tonywilson123]

No im sure a 210rpm geared hub would be ok for your needs Just not 100% sure it would be a straight swap

I really am out of my depth here, I appreciate what you are all doing on my behalf.

 

[vfr400]

I really am out of my depth here, I appreciate what you are all doing on my behalf.

Lets take a few steps back. You have a direct drive motor and presumably a 36v battery. Your 22 amp controller has a switch/setting of some sort that restricts it to 15 amps. It says on it 15amps at 250w and 22 amps at 750w. The 7 amp increase is roughly 50% above 15 amps, but 750w is 200% above 250w, so the numbers don't add up. If the output power was measured, it would be around 378w and 554w because you lose about 30% in the conversion from electric power to motive power and watts = volts x amps.

Legally, there is no restriction on how much power your controller gives to the motor. The restriction is on the rating of the motor, which is either written on it or shown in the listing from where it was bought. A motor cannot change its rating, so if it's rated for 750w at any time or in any circumstances, it's illegal. The controller has no effect on legality.

Basically, your motor is illegal, and if you want to use it, you can use whatever controller you want because nothing will change your bike's legal status other than changing the motor for one that's stamped 250w, which will give the same power as what you presently have because the output power is determined by the controller, not the motor..

Whatever the legality of your bike and despite various scaremongering stories, there is no evidence that anybody has ever been prosecuted in UK (mainland) for having an illegal bike. That includes a guy that killed a woman on a known illegal bike while going very fast. Nobody cares, but that may change in the future

 

[Tonywilson123]

Lets take a few steps back. You have a direct drive motor and presumably a 36v battery. Your 22 amp controller has a switch/setting of some sort that restricts it to 15 amps. It says on it 15amps at 250w and 22 amps at 750w. The 7 amp increase is roughly 50% above 15 amps, but 750w is 200% above 250w, so the numbers don't add up. If the output power was measured, it would be around 378w and 554w because you lose about 30% in the conversion from electric power to motive power and watts = volts x amps.

Legally, there is no restriction on how much power your controller gives to the motor. The restriction is on the rating of the motor, which is either written on it or shown in the listing from where it was bought. A motor cannot change its rating, so if it's rated for 750w at any time or in any circumstances, it's illegal. The controller has no effect on legality.

Basically, your motor is illegal, and if you want to use it, you can use whatever controller you want because nothing will change your bike's legal status other than changing the motor for one that's stamped 250w, which will give the same power as what you presently have because the output power is determined by the controller, not the motor..

Whatever the legality of your bike and despite various scaremongering stories, there is no evidence that anybody has ever been prosecuted in UK (mainland) for having an illegal bike. That includes a guy that killed a woman on a known illegal bike while going very fast. Nobody cares, but that may change in the future

thank you both for your time and comments - I have decided to take the plunge and go for the controller you suggested - I followed the thread back to topbikekit.com and ordered T09S - which is the one you recommended - it was £21 + 21.75 for DHL (could have got snail mail for £7). If i had wanted extras they were ridiculously cheap. Many thanks for your help in resolving this issue, the site is worth its weight in gold.

 

[vfr400]

You need the LCD3 to go with that controller
It will be useless on its own.

 

[Nealh]

As I mentioned and vfr has said you have to order a compatible LCD for it to work, the lcd3 is the best option though the tiny LCD4 is also an option but requires more button pressing to see different screen data. The controller and lcds although not Canbus do use comm's protocols between each other for compatibility, apart form this one can use any generic battery and BMS fitted and peripheral add on component like PAS , speed sensor and throttle etc,etc.

One also need to make sure the size of the new controller is similar to the old one if it has to fit in a certain space.

 

[scott gaza]

Sorry but swapping out a 22a controller for another 22a controller is not going to give you any more low speed torque! on a more positive note a kt system is one of the best, i use the same one myself. The only issue is the direct drive hub which will negate all the benefits of the power control system apposed to a speed controlled one. PS: There are plenty of geared hubs you can use instead of your direct drive one, you will need a low rpm around 210rpm on a 26"rim to give max low end torque.