Currie-EZip ebike Kit $289.88 - Amazon.com

[DrkAngel]

I now have the bike, but I didn't get the Currie SLA battery. I used 2 U1(lawnmower) 12Vs in series. It's heavy at 105 pounds. Where did you, DrkAngel, get the cheap Li batteries?

`~- Nehmo

Homemade Battery Packs

 

[icecube57]

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[dumbass]

I think you can use "SPORTS20" to get $55 off too. You have to use an Amazon credit card though. Coupon should be valid until June 15th.

Noisy motor, but if you don't mind the noise its pretty good otherwise.

True ... The 2008 model was noticeably noisy.
By comparison, the 2009 model was, nearly silent!
Hopefully, the newer models, improved, even more. ... ?

I am guessing that this is a clearance price, on the 2010 model.

I've read that adding a plastic spacer inside the gearbox can quiet it down a lot.

Actually that was my posting to add the plastic spacer in the gearbox. I do not recommend the average person try it. Beside it's really a hit or miss result. I've had great results on some motors and zero improvement on others. Bob

 

[DrkAngel]

2-10 times their watt rating. Meaning a legal 750w kit Double that is 1500w. 10 times that is 7500w. In no way did he say anything about 100+ volts or 72-360 volts

Volts is pressure, higher pressure = more power.
Volts x Amps = Watts
You can't force in more amps, than the windings will handle, unless you up the volts..

30A x 36v = 750w motor
300A x 36v = 7500w motor - but 36v can't push any where near that through the motors wiring!
30A x 360v = 7500w motor - Might work, if you find some one to build the controller.
But, liable to be a spectacular 4th of July Show!

Only way to up the watts, is by upping the volts or the amps.
Tho, a combination will improve HP, I can't imagine anyone getting 10HP, out of a 1HP motor ... for more than a few second ...
Note: 16ga windings should start to burn near the 50 amp point.

 

[icecube57]

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[icecube57]

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[DrkAngel]

But from a stand still the motor will draw whatever the motor wants as long as the controller current limit isnt hit. In a stall situation or coming off the line the 9x7 motor will draw up to 130A max at 36v at that point the windings can no longer accept any amps because its being limited by the resistance of the windings.

Which would make them red hot!

So the increase in amp does increase wattage output up to the limitation of the winding in extreme cases.

Actually ... in a "lock test", Increase of amps increases wattage input ... motor wattage output is zero! Heat does not count.

 

[Hillhater]

The only way to increase watt output on a hub motor is to increase the volt input!
Unless you rewind it?

Volts is pressure, higher pressure = more power.
Volts x Amps = Watts
You can't force in more amps unless you up the volts..
.

Errr ? .. have you never heard of the controller limiting the amps ???
a simple change of controller can double the power output from some stock Ebikes.

 

[icecube57]

OMG THANK YOU! Hillhater is right putting simple and to the point. You can double the amps and double the output but once the motor tops out in speed then no matter how many amps you use both stock and Super Stock are going to have the same output power due to BEMF but off the line power and acceleration you will see an increase in... input power and true output power at the same voltage with increased amps.

 

[icecube57]

With increased amps there will be increased losses in the windings as heat but there will also be an increase in output power. The stall represents the total power avaliable off the line if there was no current limit as you proceed up the power band the power output of the unrestricted magic controller motor will be greater vs a current limited motor. And it wouldnt lead to destruction cause you cant escaped BEMF in a motor.

 

[icecube57]

Output profile of a 30A controller and a 100A controller.

Also a plot of not the input power but the True OUTPUT Power.

This is a 9C 9x7 Hub.

Also the hub with the 100A controller has an increased acceleration from 9.8 secs to reach top speed to 6.1 seconds. My god where is this extra power coming from?

Whats this about the motor not only being able to accept no more than 30A.

 

[DrkAngel]

Errr ? .. have you never heard of the controller limiting the amps ???
a simple change of controller can double the power output from some stock Ebikes.

If ... the motor is deliberately over-regulated?
So ... one function of the controller is to reduce the amperage to a "safe", reasonable level?

Actually, a higher amperage controller will increase power input, most noticeable in the lower rpm region, where it is least effective, where more amperage greatly increases the percentage of damaging heat, and a comparatively minor increase in power output!

 

[Floont]

...
The only way to increase watt output on a hub motor is to increase the volt input!
Unless you rewind it?

Volts is pressure, higher pressure = more power.
Volts x Amps = Watts
You can't force in more amps unless you up the volts...

Not entirely true. Most controllers limit the current available to the motor. So, if you upgrade or alter your controller to allow the motor to take as many amps as it demands, then (and only then) is your statement true.

FA

EDIT: PS My above correction is also not entirely true, now that I think about it. You must have batteries that are capable of delivering the current that the motor is demanding too.

 

[icecube57]

I can post the results for a 5303 that will clearly show an upgrade in amps clearly increases output power.

48v and 60v show drastic changes.

 

[Floont]

I can post the results for a 5303 that will clearly show an upgrade in amps clearly increases output power...

Beating a dead horse my friend.

If the current (amp) restriction is the motor, then and only then is Drkangel is correct, voltage is the only way to increase power. Unfortunately, the reality is that controllers can and do limit current by design (icecube's point). Upgrading the controller or changing the firmware of the controller to allow more current will increase its power w/o increasing voltage. This situation is very common. I am surprised that Drkangle doesn't acknowledge this fact.

FA

 

[Hillhater]

Remember DA, we are talking of commercially sold Ebikes ...which have to meet the legal limits, so it is common for manufacturers to install a controller that limits the output to suit the requirements.
Change or modify the controller and suddenly you have more amps available at the motor for either performance.. (or smoke if there is a weak motor also :wink: )

 

[DrkAngel]

Remember DA, we are talking of commercially sold Ebikes ...which have to meet the legal limits, so it is common for manufacturers to install a controller that limits the output to suit the requirements.
Change or modify the controller and suddenly you have more amps available at the motor for either performance.. (or smoke if there is a weak motor also :wink: )

I would think it more cost effective, reasonable, to over volt -amp, the more "world standard", 250w motor, than to down regulate a 1000w, or higher, capacity motor?

Magic Pie seems to be an exception, they clearly advertise:
"Description:

* Powerful motor easily works with many voltages without modification; 24 volts outputs 500 watts, 36 volts outputs 750 watts, 48 volts outputs 1000 watts"

Also capable of 250w, presumably at 12v.

One motor-controller, capable of all listed voltages!

 

[icecube57]

Again we go back to companies not truely having a beefy motor but only swapped out controllers to increase their specs.

GM is a company that will give you data sheets for 36v and 48v but the motors are identical.

The only line of motors where size and weight does play a huge difference is the geared motors. 1 pound can make a huge difference in how much they power can handle continuously. Comparing a 4-6lb 250w model Cute or Bafang motor to a 8lb 1000w puma just isnt fare. In a case like this it would be better and safer to go to the overall larger heavier and beefier motor and derate it than trying to boost a smaller motor more amps or volts to give a better rating

Geared motors tend to be used in production 250w legal bike because watt for watt in most cases a geared motor can produce more torque with less wattage than a DD motor. With that in mind when you are matching this light weight small but shitty motor with a production ebike thats for the average unfit american rider ....they will be lucky to get to 10-15mph by themselves at at the voltage of 24 and 10A its enough to provide the assist to make anyone feel bionic. 250w on a DD hub it lame especially when part of that is just to over come the cogg/drag of the hub.

A 36v or 48v verison of a hub literally has no difference other than the controller in most cases. They arent voltage sensitive but rely on the windings to make the most out of the users situation.

WTH do you even get that its even reasonable to run a hub motor at 12v.

24x10-11A would give you your 250w... excuse me 13-14A if you count your 80% wattage output formula. Thats what would be on most entry level legal production chinese bikes.

 

[DrkAngel]

Output profile of a 30A controller and a 100A controller.

Have a link to better pictures of "Motor Simulations"?
Can't see to read anything.

 

[icecube57]

Here.. There .. Everywhere..

If you wanna see a more distict graph i can run it at 48v or select a different motor.

 

[neptronix]

In a stall situation or coming off the line the 9x7 motor will draw up to 130A max at 36v at that point the windings can no longer accept any amps because its being limited by the resistance of the windings.

Which would make them red hot! They add a fuse to prevent motor burn up.

Do you mean to say that there are fuses in 3 phase hub motors?
I haven't found any in any of the motors i've pulled apart, where are those fuses DrkAngel?

 

[icecube57]

48v graphs

 

[icecube57]

5303 Motor at 48v 30A and 100A Controller

 

[DrkAngel]

In a stall situation or coming off the line the 9x7 motor will draw up to 130A max at 36v at that point the windings can no longer accept any amps because its being limited by the resistance of the windings.

Which would make them red hot! They add a fuse to prevent motor burn up?

Do you mean to say that there are fuses in 3 phase hub motors?
I haven't found any in any of the motors i've pulled apart, where are those fuses DrkAngel?

Search the windings! Most all, should have thermal fuses, look for the odd piece, or pieces, of small tape.
Or, look for the multiple ones in the controller, or, the one in the battery pack.
Internal circuit might have surface mount, resister looking, diodes, with no markings = probable fuse function.
Often there are thermal fuses - self resetting breakers, in-line usually shielded inside a protective tube.

 

[icecube57]

Ive opened and serviced most common hub motors and several well known controllers from Keywin Lyen Off brands from ebay... ebikekit.. and golden motor... Ive had kit that came with a glass inline fuse... thats about it sir. Out of the many forum pictures ... Do you think you can point out one of these "fuses".