36V Powabyke front wheel conversion. Advice needed please.

[Mr.Linnet]

Just wondering if anyone could offer some advice please.

I recently picked up a secondhand but allegedly little used 36V 350W unbranded brushless 26" front wheel. I purchased an unbranded 36V/48V 350W brushless controller. Spent this afternoon wiring the controller to the wheel but using the original 36V power pack as the batteries had recently been replaced.

I raised the front of the bike off the ground and turned the key on the handle throttle and all three bars illuminated. I twisted the throttle but the wheel didn`t spin. I then rotated the wheel by hand whilst turning the throttle again and the wheel spun around speeding up and slowing down as I twisted the throttle.

Satisfied everything was safe I then elected to try the bike on the road ( quiet country lane ). How dis-appointing... I pedalled to start before turning the throttle. The bike picked up speed before hesitating, I eased off the throttle before twisting again but the effect was the same. It would pick up speed before slowing down as if the motor had cut out.

I returned home checked all that I could, connections and ensuring nothing was chafing etc. Couldn`t find anything so tried another road test but had exactly the same symptoms as previously. It would pull and accelerate before appearing to give the sensation that the motor had stopped operating, easing off the throttle would allow me to go through the same process again. I couldn`t get a continous acceleration.

I understand buying something secondhand is always a gamble but just wondering if anyone could offer some advice please.

Thank you.

 

[saneagle]

Just wondering if anyone could offer some advice please.

I recently picked up a secondhand but allegedly little used 36V 350W unbranded brushless 26" front wheel. I purchased an unbranded 36V/48V 350W brushless controller. Spent this afternoon wiring the controller to the wheel but using the original 36V power pack as the batteries had recently been replaced.

I raised the front of the bike off the ground and turned the key on the handle throttle and all three bars illuminated. I twisted the throttle but the wheel didn`t spin. I then rotated the wheel by hand whilst turning the throttle again and the wheel spun around speeding up and slowing down as I twisted the throttle.

Satisfied everything was safe I then elected to try the bike on the road ( quiet country lane ). How dis-appointing... I pedalled to start before turning the throttle. The bike picked up speed before hesitating, I eased off the throttle before twisting again but the effect was the same. It would pick up speed before slowing down as if the motor had cut out.

I returned home checked all that I could, connections and ensuring nothing was chafing etc. Couldn`t find anything so tried another road test but had exactly the same symptoms as previously. It would pull and accelerate before appearing to give the sensation that the motor had stopped operating, easing off the throttle would allow me to go through the same process again. I couldn`t get a continous acceleration.

I understand buying something secondhand is always a gamble but just wondering if anyone could offer some advice please.

Thank you.

There is some timing issue. Does the motor have hall sensors and are they connected?

 

[Mr.Linnet]

There is some timing issue. Does the motor have hall sensors and are they connected?

Thank you for your reply, there are no hall sensors. I dis-connected the plug from the old Powabyke wiring when I removed the old controller ( see attached photo ). The instructions for the new controller seemed to intimate the bike would run with just the motor wires connected together with the red and black battery wires and finally the throttle plug and power lock plug connected.

 

[WheezyRider]

Are you using the old Powabyke throttle with a new controller? Did the new controller come with a PAS unit, to test if that would work?

 

[saneagle]

Thank you for your reply, there are no hall sensors. I dis-connected the plug from the old Powabyke wiring when I removed the old controller ( see attached photo ). The instructions for the new controller seemed to intimate the bike would run with just the motor wires connected together with the red and black battery wires and finally the throttle plug and power lock plug connected.

That's the pedal sensor. I'm asking about whether the motor has hall sensors in it. How many wires are in the motor cable?

 

[Mr.Linnet]

Are you using the old Powabyke throttle with a new controller? Did the new controller come with a PAS unit, to test if that would work?

Its a new throttle I am using ( see photo ). The controller was just a basic 36V/48V unit.

 

[WheezyRider]

Its a new throttle I am using ( see photo ). The controller was just a basic 36V/48V unit.

Ok, can you post pictures of the motor, the controller with connections etc? Maybe cut and paste the ad for the controller from where you bought it?

 

[Mr.Linnet]

That's the pedal sensor. I'm asking about whether the motor has hall sensors in it. How many wires are in the motor cable?

With the front of the bike raised off the ground the wheel would not spin when I operated the throttle. I had to manually spin the wheel by hand to intiate the hand throttle working.

I attach a photo of the contoller wiring. Everything showing apart from the red and black power wires. The thick green, yellow and blue motor wires connected and taped up temporarily. There is a 5 pin plug coming from the motor which plugged into the contoller. A throttle and power lock plugs also connected.

It did check the connections again this morning and the thick green wire was not 100% tight, rectified this and tried it up the road. What I noticed today was it will accelerate ( after pedalling to start ) but I found when I hold the throttle roughly around a quarter of a turn and try and hold this position the bike will gather speed. Its only when I turn the throttle further that it begins to cut in and out.

Hope this make sense. I am still learning about electric bikes and sometimes struggle to understand why something wont operate correctly.

 

[Mr.Linnet]

Ok, can you post pictures of the motor, the controller with connections etc? Maybe cut and paste the ad for the controller from where you bought it?

Many thanks for your reply and interest in my posts, greatly appreciated. Photo of front wheel and wiring diagram for controller attached, hope this help

 

[saneagle]

It sounds like your battery isn't powerful enough for your controller then. What's the maximum amps written on the controller and what battery do you have?

 

[Mr.Linnet]

It sounds like your battery isn't powerful enough for your controller then. What's the maximum amps written on the controller and what battery do you have?

Many thanks for your continued help and advice in my posts. The batteries are 3 x 12V NP12-12 which are still producing nearly 39V without having been charged for the last couple of days ( see photos ).

The controller doesn`t appear to mention the maximum amps and I am struggling to get a photo with the faint markings on but says :-

Electrical Bicycle Controller.
Rated Voltage 36V/48V.
Rated Power 350W.
Phase Angle : Self Study.
Throttle Voltage 1. 1-4.2V.
Brake Level Low/High.
Date July 2023.

Hope this information may help diagnose further

 

[saneagle]

Many thanks for your continued help and advice in my posts. The batteries are 3 x 12V NP12-12 which are still producing nearly 39V without having been charged for the last couple of days ( see photos ).

The controller doesn`t appear to mention the maximum amps and I am struggling to get a photo with the faint markings on but says :-

Electrical Bicycle Controller.
Rated Voltage 36V/48V.
Rated Power 350W.
Phase Angle : Self Study.
Throttle Voltage 1. 1-4.2V.
Brake Level Low/High.
Date July 2023.

Hope this information may help diagnose further

Voltage doesn't mean very much. If you have some sort of battery level indicator, watch it when you're trying the bike. If the indicator shows the battery going down when you get cut outs, your batteries are knackered. Lead batteries lose all their capacity if you let them go down and stay down. That happens to most of them when you don't charge them for a long time.

You also get your cutting out problem if you don't fit the right type of lead batteries.

 

[WheezyRider]

As Dave said, you might be able to get a decent voltage after charge, but if the batteries are old that's no indication of how much current they can supply under load. When testing car batteries we used to fully charge them, then disconnect the ignition coil and turn the engine over and measure the voltage. If it went below 9.7V when cranking then the battery was scrap. My guess is once you get to a certain current draw the battery voltage sags below 31 V or so and then the controller steps in and cuts power as that is the low voltage cut off level.

 

[Mr.Linnet]

Many sincere thanks saneagle and WheezyRider for your replies. I really appreciate both of you taking an interest in this thread and trying to help me .

The lead acid NP12-12 batteries aren`t that old probably three months at most, I replaced the original Powabyke batteries when I first acquired the bike. I have charged them this afternoon and they are presently showing just over 41V.

There are three bars on the throttle indicator, I will take the bike for another road test this evening taking special notice of how the indicator power bars fare.

It seems my best bet is to try a 36V lithium battery pack on the bike, if I understand the situation correctly. This being the case, what sorted of amp hours would you suggest? Would something like this suffice and do a decent job?

36V15Ah Down Tube Battery Li-ion Battery Electric Bicycle Bottle Lockable USB | eBay

Find many great new & used options and get the best deals for 36V15Ah Down Tube Battery Li-ion Battery Electric Bicycle Bottle Lockable USB at the best online prices at eBay! Free delivery for many products.

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Many thanks in anticipation

 

[saneagle]

Many sincere thanks saneagle and WheezyRider for your replies. I really appreciate both of you taking an interest in this thread and trying to help me .

The lead acid NP12-12 batteries aren`t that old probably three months at most, I replaced the original Powabyke batteries when I first acquired the bike. I have charged them this afternoon and they are presently showing just over 41V.

There are three bars on the throttle indicator, I will take the bike for another road test this evening taking special notice of how the indicator power bars fare.

It seems my best bet is to try a 36V lithium battery pack on the bike, if I understand the situation correctly. This being the case, what sorted of amp hours would you suggest? Would something like this suffice and do a decent job?

36V15Ah Down Tube Battery Li-ion Battery Electric Bicycle Bottle Lockable USB | eBay

Find many great new & used options and get the best deals for 36V15Ah Down Tube Battery Li-ion Battery Electric Bicycle Bottle Lockable USB at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

Many thanks in anticipation

Amp-hours isn't important. The more you have, he further you can go. What is important is the amps. It's not clear how many amps your controller allows. It's rated for 350w, which normally means 700w max, which is roughly 20 amps at 36v. Your battery needs some headroom over that, so 25A minimum, and 30amps recommended. that puts you in the realm of more expensive cells, not the cheapest lithium batteries. What you need to look for in the listing is say 25A continuous, and more than that max, typically 40A sometimes listed as 750w or 1000w batteries.

 

[Mr.Linnet]

Amp-hours isn't important. The more you have, he further you can go. What is important is the amps. It's not clear how many amps your controller allows. It's rated for 350w, which normally means 700w max, which is roughly 20 amps at 36v. Your battery needs some headroom over that, so 25A minimum, and 30amps recommended. that puts you in the realm of more expensive cells, not the cheapest lithium batteries. What you need to look for in the listing is say 25A continuous, and more than that max, typically 40A sometimes listed as 750w or 1000w batteries.

Thats great saneagle, many thanks. It has given me some figures to work with and research. I will however be back with my findings asking for re-assurance that the battery pack it find is suitable .


Just to confirm your suspicions I enclose a couple of photos of road test short while ago. When I turn the throttle the power indicator goes from three bars to zero, when the motor cuts out I ease off the throttle and the power bars return to three.

Many thanks again

 

[WheezyRider]

Personally, I would not get anything less than 15Ah on a heavy bike if you want to do reasonable miles and have enough of a reserve for winter use, when cold weather reduces the effective capacity.

It is important to look at current rating, you have a motor which is a little bigger than the normal 250W that the law allows. However, I have been using Yose Power silverfish batteries at 28 A peak, so over 1 kW peak and up to 900W continuous and they have been fine, even though they are really only rated for 20 Amps continuous. 700 W at 36 V is just over 19 A, so it should be just about ok (within certified limits) with a Silverfish, But...looking at the Yose Power website for a 350W motor, they recommend their Hailong type battery in their kits including battery (which are currently cheaper than the Silverfish anyway). It has a max continuous current rating of 30A, which is better than the Silverfish:

36V15.6Ah/36V17.4Ah/48V13Ah HL1-2 Hailong Down Tube Lithium-ion E-bike

1.Technical Data 2.Warm tips*A 3pins charger will be sent with 36V 15.6Ah battery. But 3pins charger or DC2.1 charger are sent randomly with 48V 12.5Ah battery.*Please read the instruction manual carefully after received the package, this will help you to use the product effectively.*Battery...

www.yosepower.co.uk

It's not just the motor rating you need to look at. There should be a sticker on the controller to tell you the number of amps it can supply. What does it say? 15 A, 20A?

 

[Mr.Linnet]

Personally, I would not get anything less than 15Ah on a heavy bike if you want to do reasonable miles and have enough of a reserve for winter use, when cold weather reduces the effective capacity.

It is important to look at current rating, you have a motor which is a little bigger than the normal 250W that the law allows. However, I have been using Yose Power silverfish batteries at 28 A peak, so over 1 kW peak and up to 900W continuous and they have been fine, even though they are really only rated for 20 Amps continuous. 700 W at 36 V is just over 19 A, so it should be just about ok (within certified limits) with a Silverfish, But...looking at the Yose Power website for a 350W motor, they recommend their Hailong type battery in their kits including battery (which are currently cheaper than the Silverfish anyway). It has a max continuous current rating of 30A, which is better than the Silverfish:

36V15.6Ah/36V17.4Ah/48V13Ah HL1-2 Hailong Down Tube Lithium-ion E-bike

1.Technical Data 2.Warm tips*A 3pins charger will be sent with 36V 15.6Ah battery. But 3pins charger or DC2.1 charger are sent randomly with 48V 12.5Ah battery.*Please read the instruction manual carefully after received the package, this will help you to use the product effectively.*Battery...

www.yosepower.co.uk

It's not just the motor rating you need to look at. There should be a sticker on the controller to tell you the number of amps it can supply. What does it say? 15 A, 20A?

Thank you for your reply, unfortunately there is no mention of amps on the controller ( please see my reply #11 ). Having said this I did keep a copy of my receipt/invoice which does mention Rated Current 31A.

Hope this is helpful.

 

[WheezyRider]

I would buy a battery with a charger, that way you can be reasonably sure it will be right type and voltage etc.

It may be possible to tweak the Powabyke charger to give you 42 V, but unless you are happy to open up a mains appliance and find the right potentiometer and check the output with a calibrated digital voltmeter (assuming it even has one, not all PSUs have them), it's not worth the hassle.

31 A controller? That sounds like a beast. Normally controllers for 250/350 W are 15 to 20 A. If your controller is trying to supply 31 A at full power, no wonder your lead acids are struggling! If you stick with this controller, you will be looking at higher end battery packs, which won't be cheap. The other issue is 250 or 350 W motors are normally designed for 25 A max on the power wires. If the controller is pumping in 31 A, that may be a problem.

I'm currently away from home at the moment, where my bike is, so I can't give you a pic of inside of the box right now. But it's quite simple, a 3 sided box of 9 mm external grade ply, with two strips of wood on the bottom so it sits securely on the diagonal bottom tube and does not wobble around. It is held together with external grade wood glue and then lacquered and painted. I put an old inner tube on the diagonal bottom tube so the paintwork does not get rubbed off etc and vibrations are absorbed.

I made the box as the battery would not fit inside the original plastic case that the SLA batteries were in. It also gave me somewhere to put the controller and hide excess cables.

 

[Cadence]

But...looking at the Yose Power website for a 350W motor, they recommend their Hailong type battery in their kits including battery (which are currently cheaper than the Silverfish anyway). It has a max continuous current rating of 30A, which is better than the Silverfish:

36V15.6Ah/36V17.4Ah/48V13Ah HL1-2 Hailong Down Tube Lithium-ion E-bike

1.Technical Data 2.Warm tips*A 3pins charger will be sent with 36V 15.6Ah battery. But 3pins charger or DC2.1 charger are sent randomly with 48V 12.5Ah battery.*Please read the instruction manual carefully after received the package, this will help you to use the product effectively.*Battery...

www.yosepower.co.uk

Sorry to contradict you, but that isn't correct. All of the YosePower 350w. kits on the UK website that include a battery have the HL1 which has a max continuous current rating of 20A:-

36V13Ah HL-I Down Tube Lithium-ion E-bike Battery – YOSE POWER UK

One of the pictures has "fit Motor Power 36v700w." For some strange reason, the only kit with an HL1-2 36v/15.6A (30A max. continuous) on their UK website is a 250W. front kit!
Having said that, I'm running my Yosepower 36V. 18A max controller at 16A max at the moment and was musing over replacing it with a KT 09S 22A controller, but other than better "torque simulation" control I can't see much advantage as I would be limited by the 20A max rating of my HL1 battery.