Curious about the difference between allowed wattage for 250W LPM ebikes and normal EU ebike legislation

Bonzo Banana

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Sep 29, 2019
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The Wisper full throttle ebikes make use of the 250W LPM moped legislation and what would be a realistic and allowed maximum controller current for such ebikes? Does it follow the same rules as the EU ebike certification in that a motor can be rated as 250W despite the controller feeding it up to 25A at 36V and still classed as a 250W ebike or does the 250W LPM legislation have a greater limit on power. I've not seen it discussed. Looking at the Wisper full throttle ebikes they all look fairly low power to me all with small hub motors currently.


As is shown on this site the Department for Transport allowed for ebike kits to have twist and go throttles and they didn't need to go through the type approval process but they still need to comply with the 250W LPM legislation rather than the EU ebike certification. So realistically how much power can such a kit have and still be legal? What would be a realistic maximum continuous current rating from the controller for 250W LPM?

I guess this is a question for Wisper in how far they can push wattage and still get type approval for their ebikes? Have they even tried to get a mid-drive or high power hub motor ebike through the type approval process?
 

Benjahmin

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Nov 10, 2014
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Isn't the only stipulation on maximum speed and maximum continuous rated power of the motor (nothing to do with controller power) the same as eapc. It's the full acting throttle that makes it an LPM.
I'm sure Flecc will put me right.
 

flecc

Member
Oct 25, 2006
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The Wisper full throttle ebikes make use of the 250W LPM moped legislation and what would be a realistic and allowed maximum controller current for such ebikes? Does it follow the same rules as the EU ebike certification in that a motor can be rated as 250W despite the controller feeding it up to 25A at 36V and still classed as a 250W ebike or does the 250W LPM legislation have a greater limit on power.
Just as for EAPCs, there is no actual current rating for 250W LPM, since they have to comply in all respects, (other than the fitted fully acting throttle) to the EAPC regulations and type approval exemption.

So the 250W LPM bikes from Wisper have exactly the same motor and controller as their regular EAPCs, with the same up to 250 watt continuous nominal rating. They merely have the throttle connected and certification added to make them 250W LPM.

Remember it is not a change in the law, it is merely a Ministers permission for Great Britain only to bypass the throttle law. They do not go though Type Approval, only MSVA, single vehicle approval.
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Craiggor 2

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May 30, 2018
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Just as for EAPCs, there is no actual current rating for 250W LPM, since they have to comply in all respects, (other than the fitted fully acting throttle) to the EAPC regulations and type approval exemption.

So the 250W LPM bikes from Wisper have exactly the same motor and controller as their regular EAPCs, with the same up to 250 watt continuous nominal rating. They merely have the throttle connected and certification added to make them 250W LPM.

Remember it is not a change in the law, it is merely a Ministers permission for Great Britain only to bypass the throttle law. They do not go though Type Approval, only MSVA, single vehicle approval.

MSVA:

Ministers Single Vehicle Approval
.
MSVA is Motorcycle Single Vehicle Approval. After passing you receive a MAC Ministers Approval Certificate.
 

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Wisper Bikes

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It’s worth mentioning that to obtain approval an EAPC must have a stand. It must also have working front and rear lights that work off the same switch. So our trail / off road models cannot be approved unless we fit them.

All the best, David
 

Bonzo Banana

Esteemed Pedelecer
Sep 29, 2019
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Just as for EAPCs, there is no actual current rating for 250W LPM, since they have to comply in all respects, (other than the fitted fully acting throttle) to the EAPC regulations and type approval exemption.

So the 250W LPM bikes from Wisper have exactly the same motor and controller as their regular EAPCs, with the same up to 250 watt continuous nominal rating. They merely have the throttle connected and certification added to make them 250W LPM.

Remember it is not a change in the law, it is merely a Ministers permission for Great Britain only to bypass the throttle law. They do not go though Type Approval, only MSVA, single vehicle approval.

MSVA:

Ministers Single Vehicle Approval
.
I find the EU certification for ebikes absolutely absurd which I may have mentioned before. However trying to work within its nonsense how much can you push wattage. I know people here are claiming there is no wattage restriction as long as the motor meets the 250W rating !? However there is a maximum wattage that ebikes are selling under 250W certification. I think Bosch have done up to 26A at 36V and maybe others have gone higher with 48V battery systems. As far as I am aware there are no 1200W ebikes being sold as 250W under EU legislation. It seems to be around 750W ebikes that are sold as 250W in Europe which may peak to 1000W but are not continuous at that wattage. Some have pushed it a little more above 750W but not by a huge amount. Maybe 900W absolute maximum?

Ultimately you have to set a wattage limit somewhere and copying the limits set by mainstream manufacturers would seem realistic or is that a step too far, should we be pegging wattage just below those brands like Bosch which push to the limits for legal safety? Bosch have pushed to about 900W and got away with it so maybe 800W limit would be safe for an ebike kit with a so called 250W rated motor that only assists to 15.5mph?

Ultimately it is the controller that dictates real motor wattage and assistance speed, the motor just uses the power the controller supplies. It feels to me that the Chinese brands that have finally got wise to the EU certification are at 750W pretty much with only peak power to 1000W which they rarely would achieve. They seem to be pegged just slightly below the e-mountain bike mid-drive motors on the market which I'm guessing they feel is safe legal position.

I'm a heavy person and want to use the maximum power I can without the fear of having my ebike stolen by the police. For general long distance riding I want the reliability, strength and reduced drivetrain wear rate of a hub motor even though I prefer mid-drive for off-road ebikes.
 

Bonzo Banana

Esteemed Pedelecer
Sep 29, 2019
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462
It’s worth mentioning that to obtain approval an EAPC must have a stand. It must also have working front and rear lights that work off the same switch. So our trail / off road models cannot be approved unless we fit them.

All the best, David
So no actual restrictions on wattage of the motor. You can pretty much use any Wisper ebike even a mid-drive motor model with a fairly high current controller as long as legally sold as 250W? I see you do a model with a 100Nm very high torque mid-drive motor and no restrictions on that? 100Nm is quite impressive that is more torque than most e-mountain bikes on the market. So you can combine a twist and go throttle with 100Nm of torque legally?
 

Peter.Bridge

Esteemed Pedelecer
Apr 19, 2023
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I find the EU certification for ebikes absolutely absurd which I may have mentioned before. However trying to work within its nonsense how much can you push wattage. I know people here are claiming there is no wattage restriction as long as the motor meets the 250W rating !? However there is a maximum wattage that ebikes are selling under 250W certification. I think Bosch have done up to 26A at 36V and maybe others have gone higher with 48V battery systems. As far as I am aware there are no 1200W ebikes being sold as 250W under EU legislation. It seems to be around 750W ebikes that are sold as 250W in Europe which may peak to 1000W but are not continuous at that wattage. Some have pushed it a little more above 750W but not by a huge amount. Maybe 900W absolute maximum?

Ultimately you have to set a wattage limit somewhere and copying the limits set by mainstream manufacturers would seem realistic or is that a step too far, should we be pegging wattage just below those brands like Bosch which push to the limits for legal safety? Bosch have pushed to about 900W and got away with it so maybe 800W limit would be safe for an ebike kit with a so called 250W rated motor that only assists to 15.5mph?

Ultimately it is the controller that dictates real motor wattage and assistance speed, the motor just uses the power the controller supplies. It feels to me that the Chinese brands that have finally got wise to the EU certification are at 750W pretty much with only peak power to 1000W which they rarely would achieve. They seem to be pegged just slightly below the e-mountain bike mid-drive motors on the market which I'm guessing they feel is safe legal position.

I'm a heavy person and want to use the maximum power I can without the fear of having my ebike stolen by the police. For general long distance riding I want the reliability, strength and reduced drivetrain wear rate of a hub motor even though I prefer mid-drive for off-road ebikes.
Woosh do a 48v 250w certified motor with a 17a controller (by my calculations peak input power 816 w at 48v, more when the battery is full)


I think this is optimised for heavy riders / hill climbing ability (IE high torque winding)
 

saneagle

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Oct 10, 2010
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I find the EU certification for ebikes absolutely absurd which I may have mentioned before. However trying to work within its nonsense how much can you push wattage. I know people here are claiming there is no wattage restriction as long as the motor meets the 250W rating !? However there is a maximum wattage that ebikes are selling under 250W certification. I think Bosch have done up to 26A at 36V and maybe others have gone higher with 48V battery systems. As far as I am aware there are no 1200W ebikes being sold as 250W under EU legislation. It seems to be around 750W ebikes that are sold as 250W in Europe which may peak to 1000W but are not continuous at that wattage. Some have pushed it a little more above 750W but not by a huge amount. Maybe 900W absolute maximum?

Ultimately you have to set a wattage limit somewhere and copying the limits set by mainstream manufacturers would seem realistic or is that a step too far, should we be pegging wattage just below those brands like Bosch which push to the limits for legal safety? Bosch have pushed to about 900W and got away with it so maybe 800W limit would be safe for an ebike kit with a so called 250W rated motor that only assists to 15.5mph?

Ultimately it is the controller that dictates real motor wattage and assistance speed, the motor just uses the power the controller supplies. It feels to me that the Chinese brands that have finally got wise to the EU certification are at 750W pretty much with only peak power to 1000W which they rarely would achieve. They seem to be pegged just slightly below the e-mountain bike mid-drive motors on the market which I'm guessing they feel is safe legal position.

I'm a heavy person and want to use the maximum power I can without the fear of having my ebike stolen by the police. For general long distance riding I want the reliability, strength and reduced drivetrain wear rate of a hub motor even though I prefer mid-drive for off-road ebikes.
There's no limit on power. Have a look at what Heinzmann claim for their dual motor 250w system system. How much power do you think the 250w Amazon delivery trucks make? There are also many 250w pedicabs that make a lot more power than Bosch MTBs. All you need is a motor that's rated at 250w and the police can't touch it. I have first hand experience of that:

A couple of years back a company had their pedicabs seized by the police because a clever policeman used a device to measure current and calculated the maximum power from the battery voltage. I sent the fleet owner a letter explaining the law and the science, which his solicitor passed on to the police. The chief constable then apologised and offered him compensation.
 

flecc

Member
Oct 25, 2006
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However there is a maximum wattage that ebikes are selling under 250W certification.
No there isn't. How many times do we have to tell you this? The first series Ezee Torq, made in China, comfortably peaked at over 1000 watts and seemed mostly unburstable. And the Cycles Maximus 250 watt rated Pedicab had a Lynch motor capable of continuously delivering 4kW, peaking at almost 5kW.

Ultimately you have to set a wattage limit somewhere
Why? Because you say so? There is no limit other than the best design compromise for the best combination of range and performance. That system works perfectly ok as the S class shows. The law on that was changed from 250 to 500 watt notional limit to better enable them to reach their permitted 45kph. However, using the 500 watt rating notional tolerance to the full meant poor ranges, so the manufacturers have almost all settled on a 350 watt rating compromise, which like the EAPCs means up to about double that. This shows very clearly that designers and manufacturers can be trusted to specify what suits the purpose best and not abuse the tolerance.

I'm a heavy person and want to use the maximum power I can without the fear of having my ebike stolen by the police. For general long distance riding I want the reliability, strength and reduced drivetrain wear rate of a hub motor even though I prefer mid-drive for off-road ebikes.
So have what suits you for each purpose. The police don't and cannot test the actual power, so label 250 watts accordingly, just as the manufacturers do. So long as you don't have a fully acting throttle and the bikes are restricted to a maximum of 17 mph with assistance, you won't be troubled by the police.
.
 
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Nealh

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Aug 7, 2014
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The Woosh 816w is the battery power that can be drawn and not the power the motor takes, if one allows for the power loss due to the ineffcacy one expects the actual motor wattage to be nearer 650w.
 

Az.

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Apr 27, 2022
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I find the EU certification for ebikes absolutely absurd which I may have mentioned before.
Once or twice maybe...
It is you who is constantly trying to put a limit on power. In my opinion EU legislation is very liberal in this aspect, however I would like to see it even less restrictive.
 
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flecc

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Oct 25, 2006
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Once or twice maybe...
It is you who is constantly trying to put a limit on power. In my opinion EU legislation is very liberal in this aspect, however I would like to see it even less restrictive.
Agreed. In fact there is no need for any power limit, a point the European Parliament made long ago. Pedelecs are inately self limiting anyway, since they can only have what a bicycle can cope with in terms of power versus range,

Push the power too far and either the range becomes ridiculously short or the battery weight and size become unacceptable.

The balance of all the factors is best left to the designers, this also giving the consumer more choice.
.
 

nigelbb

Esteemed Pedelecer
Sep 19, 2019
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Ultimately you have to set a wattage limit somewhere
Why? Restricting maximum speed is all that is needed to create a legal pedelec. Speed limits are enforced on some commercial vehicles. Roads would be a lot safer if every vehicle had its speed restricted to the legal limit
 
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Bonzo Banana

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Sep 29, 2019
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Why? Restricting maximum speed is all that is needed to create a legal pedelec. Speed limits are enforced on some commercial vehicles. Roads would be a lot safer if every vehicle had its speed restricted to the legal limit
Well as you ramp up wattage you also increase the weight of batteries, motors and other hardware to support that weight. Most sensible ebike markets do have a wattage restriction. I don't want to be on a shared path with a 120kg ebike coming at me down a hill with assistance off at 35mph. I think in China they have an ebike class with a 20kg weight restriction. High wattage also means high acceleration which is again a safety issue.
 

Benjahmin

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And with greater weight comes greater cost, less range and restricted handleability in terms of getting up steps or into the shed etc. So it becomes self limiting as shown with the 350w speed pedelecs in Germany.
Most sensible ebike markets do have a wattage restriction.
Do they? Where's that then? How does that work? What's the numbers? Is it any good? Is it something that could be put forward for adoption here?
.
 
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Bonzo Banana

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Sep 29, 2019
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No there isn't. How many times do we have to tell you this? The first series Ezee Torq, made in China, comfortably peaked at over 1000 watts and seemed mostly unburstable. And the Cycles Maximus 250 watt rated Pedicab had a Lynch motor capable of continuously delivering 4kW, peaking at almost 5kW.



Why? Because you say so? There is no limit other than the best design compromise for the best combination of range and performance. That system works perfectly ok as the S class shows. The law on that was changed from 250 to 500 watt notional limit to better enable them to reach their permitted 45kph. However, using the 500 watt rating notional tolerance to the full meant poor ranges, so the manufacturers have almost all settled on a 350 watt rating compromise, which like the EAPCs means up to about double that. This shows very clearly that designers and manufacturers can be trusted to specify what suits the purpose best and not abuse the tolerance.



So have what suits you for each purpose. The police don't and cannot test the actual power, so label 250 watts accordingly, just as the manufacturers do. So long as you don't have a fully acting throttle and the bikes are restricted to a maximum of 17 mph with assistance, you won't be troubled by the police.
.
A huge part of this forum is those complaining about illegal ebikes many of which are much lower power than those claiming to be 250W. Often these ebikes have a speed limiting option and then being hub motor based their power requirements massively reduce. Now we have people claiming there is almost no limit on wattage for 250W based ebikes which is just ridiculous in how sensible certification and legislation should be written. Don't you understand the ridiculous vagueness about this ebike certification is its problem. Certification should be written with clearly defined rules that means a fairly rigid specification which allows for easy enforcement. The more I read here the more ridiculous the legislation gets. We already have tiny mini ebikes with batteries barely over 100Wh to huge e-mountain bikes with motors close to 100Nm all claiming to be 250W. Can you imagine this applied to vacuum cleaners where every vacuum cleaner be it a tiny handheld mains vacuum to huge industrial vacuum all claiming to be 250W? The deeper you get into it the more ridiculous and stupid the legislation gets hence the madness trying to enforce it.

Why is the certification even focused on the motor surely it is the controller that dictates the power that is delivered to the motor and dictates speed. Any logical attempt on ebike certification should be focused on the controller not pretend 250W stickers on motors that can take far more than 250W.

Again this is not about me. We see a huge amount of people questioning the 250W rating and no surprise as people argue here there is pretty much no real connection with 250W at all with vastly higher wattages allowed under this certification. It's just a matter of applying a sticker to a motor that can work at a huge range of different wattages one of which is 250W. You couldn't make it up. In the end the 250W rating is utterly meaningless and should just be replaced with a '15.5mph / 25Km/h restricted sticker' which would make sense and be clear to all.

I completely stand by my comments that certification should never be written in such an open and amateur way without clearly defined parameters of power and effectively now we have people at risk of prosecution and having their ebike taken purely through lack of a sticker claiming to be 250W. It's utter nonsense.
 

Bonzo Banana

Esteemed Pedelecer
Sep 29, 2019
803
462
There's no limit on power. Have a look at what Heinzmann claim for their dual motor 250w system system. How much power do you think the 250w Amazon delivery trucks make? There are also many 250w pedicabs that make a lot more power than Bosch MTBs. All you need is a motor that's rated at 250w and the police can't touch it. I have first hand experience of that:

A couple of years back a company had their pedicabs seized by the police because a clever policeman used a device to measure current and calculated the maximum power from the battery voltage. I sent the fleet owner a letter explaining the law and the science, which his solicitor passed on to the police. The chief constable then apologised and offered him compensation.
Again this highlights the ridiculous certification surely and how power limits aren't clearly defined for the legislation. I don't want to on a shared path with a 4ft wide electric van heading towards me. I seem to remember the old UK ebike legislation had weight limits of 40kg for ebikes and 60kg for e-tricycles. These seemed like very sensible weight limits for such vehicles. Were these weight limits abolished with the EU certification or perhaps increased? How heavy can an ebike go nowadays and still be allowed access to shared paths and vulnerable pedestrians? Is it another element of the ridiculous and amateur EU ebike legislation where they are utterly clueless what they are doing.
 

Bonzo Banana

Esteemed Pedelecer
Sep 29, 2019
803
462
No there isn't. How many times do we have to tell you this? The first series Ezee Torq, made in China, comfortably peaked at over 1000 watts and seemed mostly unburstable. And the Cycles Maximus 250 watt rated Pedicab had a Lynch motor capable of continuously delivering 4kW, peaking at almost 5kW.



Why? Because you say so? There is no limit other than the best design compromise for the best combination of range and performance. That system works perfectly ok as the S class shows. The law on that was changed from 250 to 500 watt notional limit to better enable them to reach their permitted 45kph. However, using the 500 watt rating notional tolerance to the full meant poor ranges, so the manufacturers have almost all settled on a 350 watt rating compromise, which like the EAPCs means up to about double that. This shows very clearly that designers and manufacturers can be trusted to specify what suits the purpose best and not abuse the tolerance.



So have what suits you for each purpose. The police don't and cannot test the actual power, so label 250 watts accordingly, just as the manufacturers do. So long as you don't have a fully acting throttle and the bikes are restricted to a maximum of 17 mph with assistance, you won't be troubled by the police.
.
It's not just about complying with the certification it is about not getting the police interested in you as the legislation is not clear cut there is a lot of confusion with enforcement. I do want a full twist and go throttle as allowed by the Department for transport 'type approved' exception for diy kits however I'm only really looking for throttle control while peddling for the harder bits. I just want full control when I need it although will be peddling at all times. I just don't want the cadence sensor interrupting throttle control. I absolutely hate cadence sensors and don't want to have the assistance on all the time.