GoldenMotor.com Forum
General Category => Magic Pie & Smart Pie Discussions => Topic started by: Magzy on October 11, 2010, 03:44:49 AM
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I was in a reputable e-bike shop in Sydney the other day getting a few bits and bobs for my MP project. The conversation got onto power and the owner asked "what sort of battery are you connecting up to this GM MP?"
I replied, "10AH Lifepo4 24v restricted to 10A at the controller" :I <--pokerface
"That's 240watts which is illegal" said the owner smugly.
To which I replied, "if you times this by the efficiency of the motor of 80% then this is 192W onto the road after losses" which is then just under the legal limit.
"Just as well" said the owner. "The RTA (Road Traffic Authority) was in here last month wanting to know how to connect these electric bikes up to a Dyno."
"A Dyno?!" I asked.
"yes, it's a portable device that measures output of an electric bike to see if it's over the allowable threshold of 200W output - they don't need to take bikes away for testing, they can just pull people over at the roadside and test it there and then".
"When's this going to be started" I asked. He told me didn't know but it's going to start at some point in the future.
so, assuming that my 48v 20A MP beast is over the threshold, is there a simple way to pass the dyno test by way of introducing a limiter or switch for on road use and allowing the higher voltage / amps for off road use only.
Has anyone actually done this with the MP w/ external controller?
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I'm no expert but you can wire up a switch which will limit power. i'd be interested to see what these dynos actually measured. If it is just speed then it would be easy to fool with a hidden switch to limit power/speed.
A dyno for a car is very complex and measures torque, bhp, fuelling mixtures, air temps etc etc when the car has been fully wired up with probes. But i'm not sure how much information a portable bike dyno will give.
Are E-bikes that popular in Oz? i would like to think that they must be having quite an impact on public roads for law enforcement to act in such a way.
i believe there will come a day in the UK when e-motors become a lot cheaper and kids start modding their push bikes and the law will step in because of nuisance users.
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I live in Melbourne
Confirm that the cost to implement and teach officers to use current power devices will far exceed anything realistic
I'll keep my dual pie thanks very much officer
Dual 100W that is muhuhahahahahhahaaaaa
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I cycled to and from work in sydney for over a year and only stopped for the winter this year.
I saw just 2 e-b ikes in that time.
However, driving around the inner west and specifically newtown the other week, they're all over the place because they're a green alternative to oil and appeal to the alternatives that live there.
Ebikes are set for a revolution I think in Australia. We have the perfect climate for it (i.e. it doesn't rain as much as the UK - where I lived for 6 years) and the government is ready to make money off it by attaching bikes to a dyno to see who's breaking the law.
It does not make a difference in top speed in AUS- it's the wattage output that can't legally exceed 200W.
Theoretically, you can wire up a 96v battery and limit it to 2 amps at the controller and it would be legal, conversely you could wire up 12v @ 16 amps and it would still be under the 200w limit.
with this in place it's easy to attach a resistor to the circuit that limits voltage and changes your system from a 48v to a 12v and only kicks in when you flick a switch.
As for Amperage, this would be more difficult but maybe have two controllers wired in paralell with another switch to switch between the amped up one and another set to 5A that can be switched on when needed.
Another way would be for the controller to be programmed on the fly using a usb key...
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Magzy, sorry champ but not sure where that logic came from :D
That would be like a 80Watt resistor, probably as big as my battery pack lol
And USB-Key no go, how can you possibly choose the settings? And unless its a special device, could not communicate serially.
I can near guarantee that I will never see a bike "Dyno" when you can simply use a current decent current clamp in betweent the battery and controller to get a power current reading
All readings would be out of whack unless someone is sitting on it. Electrical motors need a load to draw current to their full extent.
I say let them test my unloaded ebike to their hearts content !!!!
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You’re absolutely right Monkey, the electrical motor need a load. I’m not sure what that dyno is but I’m guessing it’s a braking device. The kind they use to measure the power on motorcycles, but in a slimier design.
The CA can, according to the manual, be rebuilt to handle this by a switch. Nothing I tried though.
Peter
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Cheers Peter
Not sure about the CA, possibly can switch the throttle circuit using a resistor there. At best I would hope it would be a current limiter circuit so you can switch the analogue voltage reference by changing a resistor, therefore allowing you to 'program on the fly' by basically creating a power/economy mode
Okay that's it.... I think I have to put my foot down and get a CA and ditch the turnigy
Hey Gary PM me 'mates rates' for a CA? hehehe
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Okay that's it.... I think I have to put my foot down and get a CA and ditch the turnigy
You will never regret buying a CA. With the advanced hookup it changes from an analyst to a controller with speed control with many options for saving power. Be carefull though, when you first start using it, it is difficult to keep your eyes on the road.
Gary
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good advice !
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What is this CA you are talking about.
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What is this CA you are talking about.
It is a cycle analyst. Probably the best onboard bicycle computer you can find. It keeps track of all sorts of data, you can see live how many amps, watts, etc you are using. How many amps you have used up, how fast you are going, etc. Aslo can also be used to control your bikes speed and power usage. I love it.
Gary
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You hear all types of things from bike shop owners. A lot of em just need to find a way to critique the ebike. Sometimes the ebike owner has problems especially if the bike performs better than a lot of what they would sell.
The Ebike owner can incite animosity among the cycle communities sometimes.
I just take it easy and when I see police I put some pedal power in.
To be honest even 35kph would be a good limit for me. Im thinking of speed limiting the bike via the CA.
The motor also can run as bad as 25% efficiency so you can put that into the shpeel you give anyone who questions the legality of the bike..
I think good power is a safe thing to have and speed should be limited IMO. Good powerfull ebike make them less of an annoyance in traffic.
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In law the RTA have no rights to do jack as there is no submission of license or an agreement between RTA and defendant what-so-ever.
You have jack getting real justice using such knowledge but I am right. Unless you require to sit and learn the road rules and sign to sumit to obey the rules, then they can not fine anyone or do jack. Not even a helmet fine should be legal IMO.
Under codes and statutes, not common law.
In all fairness.
Is nobody is going to care if a fat guy hits an old lady going 50kph down hill on a bicycle when there is an ebike going 40 kph they find reason to get revenue
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Where can I order this CA unit from (web site etc.)
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Gary at www.goldenmotor.ca sold me mine.
If thats not and option try google.
It depends on what version you want. Headach free the CASA Stand alone provides the tachometer and with a mod so you can have it do throttle controll LVC and or current controll too.
Im thinking I will install my throttle wires through the CA as it will give a few good limitations over the exsisting magic controller features.
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To be honest even 35kph would be a good limit for me. Im thinking of speed limiting the bike via the CA.
The motor also can run as bad as 25% efficiency so you can put that into the shpeel you give anyone who questions the legality of the bike..
I think good power is a safe thing to have and speed should be limited IMO. Good powerfull ebike make them less of an annoyance in traffic.
I agree with you Leslie, most bicycles are not made for high-speed usage. IMO acceleration and mountaineering are the best benefits on the e-bike.
Btw, my test rides on the ladies haven’t got any further. The right nut is still missing and the Dark lady has to be calibrated by an gps.
Peter
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Thank you for your help with the CA unit.
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Where can I order this CA unit from (web site etc.)
The Cycle Analyst is built in Canada and can be ordered from the manufacturer here: www.ebikes.ca (http://www.ebikes.ca)
It is a clever little thing.
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Where can I order this CA unit from (web site etc.)
The Cycle Analyst is built in Canada and can be ordered from the manufacturer here: www.ebikes.ca (http://www.ebikes.ca)
It is a clever little thing.
I sell them as well. Quite often when people order items from me the can get a CA from me at the same price but with no additional shipping
Gary