Limiting power down to legal levels

dont get me started on how pathetic 250w is ! If I had to commute on 250w I'd just buy a road bike and ride that, f>}^#k electric. Australias laws are so overly dramatic for electric bikes. It's like they grabbed the oldest lady politician they could find and popped her on a nanny bike and she presses the button and it gives a little pulse of power and she freaks out! "That's more than enough! It was so scary when it did 20kmh" it's just so dangerous. I was so scared.

I can out pedal any 250w bike, breaking the speed limit by 3 times! I tested the other day, 250w doesn't keep up with anything, even when pedalling, the weight of the motor and battery defeats the purpose.

Look up what happens if you hit someone on a non electric bike, you can still get your ass sued! I had a mate who ran into a lady on his BMX , 3 broken ribs, he came out of a side street too fast, taken to court he'd be done. It's only that she knew the family she didn't sue.

I daily commute and on the flat 500w is all I need to move along are normal road bike speeds, I get to work in a reasonable time, and on all levels I travel just like a fit guy on a road bike. Look at the US, 750w and 1000w in some states, it's a perfect limit. I can do my entire ride in the 750w limit and with hills. 250w forget it. 250w and you might as well just wear a helmet for walking because it's just too dangerous if you fall over.

Almost weekly I got zoomed by some toss who just thinks it's great to go full naka on his new bbshd or mxus 3k! Just skimming through gaps in the Lycra trains, it boils my blood, it's those limp cocks that are shafting normal ebike commuters and will ruin it for everyone. Basically I can see them banning any electric bike if there's a few deaths in the news.

Soon you will have to buy an ebike kit with a full ID check, the unit will be sealed and tamper proof. ADR kits, no home kits or even your own batteries. It's just nuts.

Forget power limits, book people for speeding on paths or wreckless riding. Let me get insurance and I'm happy to pay a yearly admin fee. It beats sitting in traffic, it helps ease congestion. I don't want to Lycra and have to shower at work, I just want clean easy transport. 250w forget it. 750w perfect, 40kmh limit perfect. Done ! Now go and spend time and resources on catching fiddlers or dealers. All this is a another money grab. Bring on helmets for walking with built in GPS distress beacons, padded undies and knee pads , ffs it's just getting nuts.

By the way BBS mids PAS 1 is around 250w depending on battery, get a program cable , set power to 250w. When you power on it always goes to pas 1. Limit speed, pretty sure you can do it for each pas. Ride sensibly , use the other pas on hills keep speed around 40kmh, done.
 
Thanks all for your replies.

dustNbone said:
I was thinking a bluetooth enabled controller that you can set default power level on for when the controller is first turned on. If you want to increase the power, you need to use an app on your phone to set a higher amp limit.

So you get pulled over, you turn off the bike. If the cops take it and turn it back on they get 10A or whatever you set the default to.

They give you back your bike and they go away, you pull out your phone and make your bike fun again.
Click to expand...

If one wanted to go with the above option for the BBSHD how would you go about it?

If I used my phone and a bluetooth connector along with an app like forerider or eggrider(not out yet) can I set the power level down to 200w using a programming cable? I mean so if I take the phone away it will default to 200w? That way if the bike gets tested without the phone you are golden.

Could be a slight pain to have to take your phone every time you jump on the bike but not a bad solution if it works.

Cheers
 
izeman said:
instead of your phone you could use any rfid scanner and an rfid tag that you take with you or have installed inside your bike gloves (or shoes etc)
Click to expand...

The nice thing about a phone or other bluetooth device is you can turn it off while still in proximity of the receiver. I'm not sure if you can do that with an RFID device.
 
Here is my plan first plan

Use programming cable to limit power down to about 200w

Use bluetooth adapter and phone so I can use full power

Question: If I take the phone away will the bike revert back to the 200w I set?

I seem to remember reading somewhere that the bafang controller remembers the last setting you had when you unplug the LCD so maybe this won't work?

I have also ordered a potentiometer so will play around with that too.

Cheers
 
Alan B said:
Is there a specification for how this "rated" power value is determined? Anyone with some magnets and copper wire can "manufacture" a motor, how do they determine what value to "rate" it at?
Click to expand...
no. and this is why the "most od EU" specification of 250W "rated" is stupid as bull shit. austria law claims 600W MAX wattage. that's more or less the same, but at least you can check it.
for EU legislative there is NO way to check 250W rated, but look for a sticker at your bike 8)
 
barbs00 said:
So to limit to 200w for a 52v battery (lets say 50v) I would need only 4 amps.
Click to expand...

That's input power, not output power. Don't cheat yourself that way. The ratio of motor power out to battery power in ranges from a maximum of typically 70-85% at optimum load and speed, down to 0% at stall.

I don't know what kind of control system you'd need to make the motor deliver exactly 200W over the widest possible range of speed, but that would be ideal. It would allow a weak, legally compliant bike to help meaningfully for climbing and accelerating from a stop. If you only use say 5A at 48V in order to limit motor output to 200W in the best conditions, then you'll get a lot less than 200W when climbing a hill-- when you most want the help.

It seems to me that a great project for an Australian to do would be to choose a particular motor, test it, and then make a smart controller that correlates motor RPM and efficiency to regulate controller current so that the legal limit of power is available in almost all conditions up to the speed limit.

The talk of dyno testing on one hand, and maximum watt rating on the other hand, doesn't make sense to me. I can't think of a single industrial electric motor that isn't able to greatly exceed its rated power for a short time. One or the other has to take precedence-- either the maximum motor power is limited, or its rating is limited. They are not the same thing.
 
Chalo said:
barbs00 said:
So to limit to 200w for a 52v battery (lets say 50v) I would need only 4 amps.
Click to expand...

That's input power, not output power. Don't cheat yourself that way. The ratio of motor power out to battery power in ranges from a maximum of typically 70-85% at optimum load and speed, down to 0% at stall.
Click to expand...

That's a good point. The new Arizona law is ambiguous on the point of motor power:
"ELECTRIC BICYCLE" MEANS A BICYCLE OR TRICYCLE THAT IS EQUIPPED WITH FULLY OPERABLE PEDALS AND AN ELECTRIC MOTOR OF LESS THAN SEVEN HUNDRED FIFTY WATTS AND THAT MEETS THE REQUIREMENTS OF ONE OF THE FOLLOWING CLASSES:" (italics mine)

So, what does "of less than seven hundred fifty watts" mean? Output, input, rating? It's ambiguous, so I'll use the ambiguity to my advantage.

BTW, the notion of these miserly watt limits is rather brain dead regardless of how they are worded. What really matters is limiting speed. Who cares what the motor power is? A Segway has two 1500 watt max motors. That's four times a Class 3 e-bike, yet it is allowed on most sidewalks in the U.S. Why? Speed limiting?
 
barbs00 said:
To be honest I didn't know you could do that with a CA. The price however.....my wife may kill me if I spend to much more on my bike :?
Click to expand...
barbs00,

In the USA, Sick Bike Parts (really!) sells a programmable controller separately for ~US$19.00 before shipping, but I can't say if it may or may not work with your existing hardware. I believe the controller will handle ~40A. Maybe that part will be an option for you. Check with their email tech support.

http://sickbikeparts.com/electric-shifter-kit-programmable-3000w/

I realize this would not help if the limits are set on the motor design, rather than the power produced on the road.
 
The efficiency of a motor at low speed is not all that much lower than at peak efficiency. So if a motor is 80% efficient then just feed it enough extra power to get the legal output, it will be very close. Power input is easy to measure and control using a Cycle Analyst, or by setting the controller to limit battery current and assume the midrange voltage.

The power at zero is irrelevant (and is true for a gas engine as well), it is only the torque that matters, and there will be plenty of torque due to the current multiplication of the controller at low speeds.
 
wturber said:
So, what does "of less than seven hundred fifty watts" mean? Output, input, rating? It's ambiguous, so I'll use the ambiguity to my advantage.
Click to expand...
Yes, I have two 374watt motors on the trike. :)

Now, if they really got super technical, the law only allows one motor...but I don't think they'll care.

I also don't think they'll care as long as the rider is being safe and observing local law and riding to conditions, etc. Nobody even cares that my trike is rather...different from a typical bicycle. :lol:

(no one cares about another local guy that rides a homebuilt quadricycle (pedal only, but still not a bicycle by the legal definition here); I've seen him once around metrocenter area, couple days ago, and another cyclist I know met him on the path and chatted and took some pics)





BTW, the notion of these miserly watt limits is rather brain dead regardless of how they are worded. What really matters is limiting speed. Who cares what the motor power is?
Click to expand...
Exactly. :) That's why I preferred our present law here in AZ.

A Segway has two 1500 watt max motors. That's four times a Class 3 e-bike, yet it is allowed on most sidewalks in the U.S. Why? Speed limiting?
Click to expand...
No, because Segway paid for law changes everywhere that didn't already have laws allowing them.

FWIW, I haven't seen power limits for any mobility device in the various laws I've poked around for over the years--only speed limits, and sometimes limits on where they can be used.
 
amberwolf said:
wturber said:
A Segway has two 1500 watt max motors. That's four times a Class 3 e-bike, yet it is allowed on most sidewalks in the U.S. Why? Speed limiting?
Click to expand...
No, because Segway paid for law changes everywhere that didn't already have laws allowing them.

FWIW, I haven't seen power limits for any mobility device in the various laws I've poked around for over the years--only speed limits, and sometimes limits on where they can be used.
Click to expand...

In Arizona Personal Mobility Devices are limited to speeds of 15 mph. No power limit. I strongly suspect that designing to stay within such speed limits was a key part of the success of the effort put forth by Segway to get legal access to sidewalks.
 
Reflector said:
Barbs, did you get your bluetooth via smart phone setup working?
Click to expand...

here I describe a setup to limit power/speed of a BBS motor using bluetooth or a hall switch, should work with BBSHD as well as programming is the same as the BBS02:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=94850
 
You'd have to check with Dillenger to find out. Even if it is, you might want to read some of these first:

https://endless-sphere.com/forums/search.php?keywords=dillenger&terms=all&author=&sc=1&sf=titleonly&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search
 
Thanks for the heads-up Amberwolf, I had no idea about Dillinger; I'll scratch that idea.
What I'd really like to do is emulate Fastolfe's idea. Is there a build thread on this and did he use the CA in conjunction with the original display or was he able to dispense with the latter.
His fake electrolytic capacitor is easier to hide and enables a 'dual mode' at the removal of a velcro wrapped magnet.
 
Basically (from what I understand of Fastolfe's description) he used the 'Aux pot' input on his Cycle Analyst to select a second setting.
Achieved with a reed switch secreted inside the shell of an innocuous empty capacitor shell.

I don't want to go off topic; and someone please direct me to the appropriate place if necessary.
My setup is a BBS02 in a velomobile which must have its' PAS activated by an external PAS sensor (due to a freewheel crank in between).
A CA should do the trick but I'd have to figure out whether to run the PAS sensor to the CA or into the case and patch it where the original was.

I'll watch this space.....
 
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