EPAC - How to make e-bike with Golden Motor parts legal in Europe

[Perbear]

I have now built two ebikes with GM parts, the latest using the BAC-28X series controller. I have also helped several others assembling ebikes here in Europe. Unfortunately, the controller is not suitable for a legal European ebike (EPAC) as it works now. Here are the two most important issues:

• Pedal usage sensor (Pedelec) only works when manually enabled - it should automatically be working when powering up
• Throttle overrides the pedelec sensor - it should be the other way - throttle should only work when pedaling if connected

These two important issues needs to be fixed to be able to present a GM based ebike as a legal EPAC in Europe.
In addition, the following issues should be improved somehow:

• The current pedelec sensor function uses cadence (pedal RPM) to control motor power - this is a bad solution. The ebike speed varies from the cadence dependent on gears selected so the current pedelec function may only work on single speed bikes - if it can work well at all
• A good solution would be to use a torque sensor as an optional man/machine interface (similar to what is required in the Japanese Pedelec standard)
• There should be a settable maximum speed for the controller with full power, and a settable speed for minimum power. Currently, the 250W mini motor runs faster than allowed (35 km/h with 700c wheels)
• EN 15194:2009 allows a startup mode that can activate motor without pedaling at max speed of 6 km/h. This function must be manually selected by a separate button/handle. This function would be nice to have and is currently missing.
• The brake switches are only required if pedal sensor is slow to react. If user stop pedaling and power to motor is cut before ebike has moved more than 2m no brake switches are required. This would require a better/faster pedelec sensor, but would make it possble to use original brake handles

There are also other issues related to EN 15194:2009 like IP X4 water protection, 90 cm drop test on battery and tough EMC immunity requirements. Fortunately, when the EN standard will come into force in July this year it will make a much larger market for EPAC ebike parts.

Per

[GoldenMotor]

Hi Philip Yao,

Thanks for your kind words 

In March I will start a course about building e-bikes here in Norway. Many participants are less than 18 years. So I have to be 100% certain that the bikes we build will both be safe and completely legal. Because of that I have spent a lot of money and many hours getting hold of the necessary standards and studying them. So if you need input on how to make EU compatible kit/parts please let me know. I will be glad if I can help.

Currently we need a controller that can reduce motor power gradually when bicycle speed comes close to max speed (25-27 km/h). Maybe your new BAC-28X series controller fixes this?

Kind regards,
Per

Visit www.evs24.org!

Yes per, our controller fixes this problem. If you have any questions at all, feel free to mail me.

Yao Yuan
yaoyuan@goldenmotor.com

[b-twinelec]

Per,
I am in the UK and there is a local law which slightly conflicts with European Law.
Do you know if it is clear that European Law takes precedence above national rules?
Thanks,
jb

[Perbear]

Per,
I am in the UK and there is a local law which slightly conflicts with European Law.
Do you know if it is clear that European Law takes precedence above national rules?
Thanks,
jb

According to the article http://www.bike-eu.com/facts-figures/eu-regulations/3359/new-epac-standard-for-safe-e-bikes.html :

Sixth months after the EPAC standard announcement all the European and EFTA National Standards Bodies will have implemented the EPAC standard as national standard and any previous national standards shall be withdrawn before this date. This date is July 31st 2009. The implementation of the EPAC standard varies by country. In some European countries it is compulsory by law. These countries are (as far as Bike Europe knows at this moment) France and the UK. In other countries it is part of the European product safety ruling.

As I understand this it seems that all UK EPACs (Pedelec in EU terms) that is produced or imported after July 31. 2009 must follow EN 15194.

Per

[jn]

To be an EPAC your ebike motor may not apply power to the wheel when you go faster than 27.5 km/h (25 km/h + 10% tolerance). The motor must also supply not more than 250W continous power output to the wheel. In addition, the motor can only run when the pedals are used and must gradually reduce its contribution to forward motion when the speed approaches the maximum ebike speed. Also, the motor must stop when the cyclist applies the brake.

I think the motor is gradually reducing its torque when speed increases, so no action from controller needed for that. Just stop the motor at abt. 27.5 is needed. Also brake switches are not needed if motor stops when not pedaling. Speed can be controlled by gas throttle if you pedal, no matter how fast.
For DIY  everything should be kept in KISS design, but still according to EU-legislation.

[Perbear]

The reason for the brake switches is the requirement to be able to stop the motor before the bike have moved more than 2 m after pedaling stops.  If you have brake switches your motor can continue to run until you have moved 5 m after you have stopped pedaling. When you stop pedaling the motor should stop immediately. If it does that before the bike has moved 2 m after pedlaing stops, brake switches are not required.

I suggest that the PAS magnet wheel is supplied with many more magnets (or made of punched steel with plenty "fingers" that can be sensed) to have a much better resolution/response. This is required so that the PAS senses immediately when you start or stop pedaling. I can not see any good reason for coupling the pedaling speed (cadence) to the motor speed or torque as it is done now.

It is important that the throttle only work when you pedal, if not, the ebike would not be according to EN 15194. Also, the PAS must be working as default and not as it is now where you have to switch on the PAS function every time you start the bike.

In addition, GM should add start-up mode (bike can go up to 6 km/h without pedaling) but that would require an extra switch input.

[lifeonourplanet]

Perhaps if there was a simple micro-switch, reed-switch or optic sensor that activated each time the pedal arms completed a revolution? Would it perhaps be possible to use a 555 timer circuit that kept power to the controller as long as 2 seconds? That way you only need to do a revolution of the pedals every 2 seconds to keep the controller turned on, if you stop pedaling then the controller turns off in 2 seconds. Just a microswitch a simple 555 timer with a relay that go's to the controller, perhaps to the brake switch. It's a kinda grey area to give e-bike builders an easy loophole around the new law with no need to add expensive complicated circuits. 

[Perbear]

Perhaps if there was a simple micro-switch, reed-switch or optic sensor that activated each time the pedal arms completed a revolution?

The EN 15194 requires that the motor stops before the bike has rolled more than 2 m after pedaling stops, and not 2 seconds or alternatively one revolution of the krank. This requirement makes it a bit more complicated.

I forsee a simple microcontroller board with sensor inputs for the following:
Speed sensor (inductive with one pulse per spoke passing by),
pedal sensor (with 16 or more pulses per revolution that discriminate direction of rotation),
current sensor (to limit max current),
hand/thumb throttle

The output should be the speed input to the controller plus four LEDs (power, power reduction at over current, power reduction at near speed limit, power off due to maximum speed).

The board should have a single switch input used for activating startup-mode (up to 6 km/h without pedaling) in normal usage. If the switch is kept pressed during power-on, the board LEDs become  diagnostic LEDs for the sensor inputs (one for speed sensor signal, one for pedal sensor, one for current sensor and one for throttle input - the last two has flashing speed dependent on input value)

The board should be easy to reprogram by user/owner to customize for various wheel sizes, battery current sensors and speed limits (when to start to reduce power, and when to cut power).

Throttle speed ramp-up should also be tunable by user to have the bike behave smooth in various circumstances; imagine when speed signal to controller has been turned off due to stop of pedaling, and the user start pedaling again - the motor must not be activated abruptly. Also for regenerative braking is smooth handling very important.

Does anyone feel the need to make such a microcontroller board? 
 

[Philip Lynott]

Hi Perbear,

I have a question for you if you don't mind - do you think an ebike would be considered legal under european rules if it had 2 x 250W motors i.e. one on the front and one on back?,

This would allow the bike to climb hills and accelerate better without allowing the bike to reach 'high' speeds.

I have built a bike with 2 motors controlled by one throttle and two controllers it's quite straight forward.

Thanks

[Perbear]

Hi Perbear,

I have a question for you if you don't mind - do you think an ebike would be considered legal under european rules if it had 2 x 250W motors i.e. one on the front and one on back?,

Philip,
The max power is specified to 250W continous rated power. It is in some sections specified as motor power but in the major definitions like Scope in section 1 and in the power measurement appendix D.1 the reference is to "output power" of the cycle. Using two motors will not allow doubling the cycles output power.

But:
The EN 15194:2009 states the following definition in section 3.22 of Continous rated power: "Continous (or constant) output power specified by the manufacturer, at which the motor reaches its thermal equilibrium at given ambient conditions". In a different section the thermal equilibrium is when the temperature in the motor does not change more than 2K in an hour.

With suitable electronics it should be possible to use the thermal mass inside the motor for having extra peak/burst output power without added complexity and weight from using two motors. This can be used together with a tilt sensor or a power boost button, typically for going uphill. As long as you have a thermal sensor or something that reduces power to the motor when it comes close to the max temperature, it would be OK. But remember that your system must automatically reduce power to zero when reaching 25 km/h to be legal.

[Philip Lynott]

Thanks Per,

It think your saying 2 x 250W motors would not be legal, this is a pity because the characteristics of hub motors mean that 2 x 250W motors would have more or less the same top speed as 1 x 250W while still having greater acceleration.

Would you agree that the californian rules are more realistic than the EU ones?, in California they can have 1000W motors a top speed of 35km/h and no requirement to pedal.

If it's good enough for California, China and probably other countries why can't we do it in europe ? - you may have more insight into this as you have a copy of the standard

- I personally believe europe does not want to lose tax revenues for all of the two-stroke scooters that could be taken off the streets if proper e-bikes were allowed

[Perbear]

- I personally believe europe does not want to lose tax revenues for all of the two-stroke scooters that could be taken off the streets if proper e-bikes were allowed

I agree. There is no other logical explanation why the power is limited to only 250W but to prevent loosing tax income.  Maybe we should start our own EPAC EU-lobby?

[architect]

Hey guys,

i am from Australia and the laws here only allow 200w max motors. What many Aussie e bikers are doning is putting 500w motors on their bike and taking the rist with the law.... most police here as I would assume the same in europe do not have the tools to test how powerful the motor is.... if I was u I would ignore the laws and build a bike that can get u up hills with ease and respect the speed limit... I cannot see that the police would have the time to check every bike that has a motor just to give a stupid fine.

anyway just thought I would make comment about unjust regulations that are preventing people from using alternative green power transport.

cheers.

[Philip Lynott]

I am serious about ebikes and will start a lobby, I would imagine it would take years to make any changes though as the EU rules have just been set,

Per, do you know how to go about lobbying the government ?,

Architect, I have a 1000W motor in Ireland where the limit is 250W and have not been called up on it by the police (yet), I want to change the laws because I think the laws not reasonable, I don't like the feeling of always being wary of seeing cops and I would like to sell ebikes and can't see a very big market for the legal models.

[stl_recum]

I don't thik there is any laws or regulations in any of the countries that say you can not build an e-bike with motor greater than 200W, 250W or 750W.

You just have to treat them as motorcycles and abide by the appropriate regulations.

Off read there is no limit in any country.

I don't what people on e-bike going 30 plus MPH on our peaceful bike trails.

The limits are all about safety and creating a class of vehicle.