Mac woes...

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gazmunch   100 mW

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Mac woes...

Post by gazmunch » May 19 2014 9:49am

I have a silver 8t Mac (that I know to be working fine) in a 24" wheel, running on a 48v 20ah Lifepo4 through a Lyen 12 fet sensored controller. I'm using the wiring that the previous owner suggested (Blue-yellow, yellow-blue, green-green), but I'm only getting a top speed of 22mph. It should be getting about 30-35amps but full throttle after initial acceleration (to 22mph) it's only taking 15amps. I've tried a load of other phase and hall combinations, but still nothing more than 22mph. I really don't know what it could be that is causing this, and am hoping that you might be able to point me in the right direction. The controller has never been altered, and the CA settings are set to max amps and max speed.

Any idea what's going on?

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izeman   100 GW

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Re: Mac woes...

Post by izeman » May 19 2014 10:02am

could be that the controller is programmed wrong, or that you have to attach a 3way switch, as the controller is running on low-setting.
do you have a programming cable and a 3-way switch?
i personally would try the switch first. i have a 90% feeling that the missing switch is causing this problem.

gazmunch   100 mW

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Re: Mac woes...

Post by gazmunch » May 19 2014 10:04am

I've not got a three way switch or a programming cable :(

I have used this controller on a dd motor before and it was sending through 30-35 amps continuous without issue. Not sure why it would be different with this motor.

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izeman   100 GW

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Re: Mac woes...

Post by izeman » May 19 2014 10:06am

gazmunch wrote:I've not got a three way switch or a programming cable :(

I have used this controller on a dd motor before and it was sending through 30-35 amps continuous without issue. Not sure why it would be different with this motor.
hmmm strange. so you used this very same controller with a different motor (w/o switch) and it was working fine?
anything else (electronics wise) you changed? throttle maybe not outputting full voltage?

gazmunch   100 mW

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Re: Mac woes...

Post by gazmunch » May 19 2014 10:09am

The only other change I made was adding an ebrake lever. That couldn't be having an effect on anything other than cutting the motor out when it's depressed, right?


amigafan2003   1 kW

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Re: Mac woes...

Post by amigafan2003 » May 19 2014 11:43am

Is that speed loaded (i.e. you on the bike) or unloaded (i.e. on a stand)?

22mph sounds about right for an 8t in a 24" wheel on 48v under load.

No load speed should be about 28mph.

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izeman   100 GW

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Re: Mac woes...

Post by izeman » May 19 2014 12:06pm

you're right. i didn't check the to be expected speed settings. 8t in a 24" wheel is not super fast.
8t = 24 mph at 38v in a 26" wheel.
so 24mph * 24" / 26" * 44v / 38v= 25mph, which is close to what you have.

gazmunch   100 mW

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Re: Mac woes...

Post by gazmunch » May 19 2014 12:52pm

No, that's not right at all. I should be getting 29mph at 48v according to the simulator, plus extra when my battery is hot of the charger. Something is definitely wrong.

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izeman   100 GW

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Re: Mac woes...

Post by izeman » May 19 2014 1:05pm

look here: http://em3ev.com/store/index.php?route= ... duct_id=52
it give quite accurate to be expected speeds for different windings.
if you're referring to ebikes.ca simulator i'm not sure what motor the bmc_v2_trq/spd refer to. but i think none of them is 8t. but i could be wrong.
what current do you see during takeoff. what are your max readings? what are your reading going steep uphill?

gazmunch   100 mW

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Re: Mac woes...

Post by gazmunch » May 19 2014 1:14pm

I know for a fact that this motor can go much faster than it is currently going.
It's getting 30amps on takeoff, but goes down to 15amps once it gets to 22mph. I'm not going to attempt to take it up a hill while it's not right.

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newb   100 W

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Re: Mac woes...

Post by newb » May 19 2014 2:10pm

hey mate,

an 8t mac in a 24" wheel @ 52-54v +/- a V will be 26ish mph, in a 26" wheel 30-32mph.
but a 10t mac in a 24" wheel will be 22-24mph, sure it's not a 10t?

if it's not, then try disconnecting everything but the battery, throttle, hall/phase wires, then run it again. any change according to the buttymeter?

still not happy, any chance u still have the dd motor to confirm the controller still provides those same numbers as before?

and when using the sim use the bpm to equal an 8t mac, numbers are very close in my experience.

one last thing, a 10t mac in a 24" should pull max settings then drop off fairly
quickly so what you are experiencing is not surprising.

Good Luck

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izeman   100 GW

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Re: Mac woes...

Post by izeman » May 19 2014 3:51pm

if it draws 30a on takeoff that shows that the controller is programmed correctly. of course it goes down to 15a when it has reached it's top speed. that's how it should be.
what is the no load draw (lifting the wheel and going wot). what shows the ca? speed and current?

gazmunch   100 mW

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Re: Mac woes...

Post by gazmunch » May 19 2014 3:58pm

Right gents,
Just got back from a test ride without the Cycle Analyst out ebrakes plugged in and it's made no difference.
Apparently there is an issue with these motors running on this Lyen controller. The same controller hardware, but from cellman apparently does not cause this problem, so it sound like it is the controller software that is the problem. Where I go from here exactly, I'm not sure...

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cal3thousand   1.21 GW

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Re: Mac woes...

Post by cal3thousand » May 19 2014 4:22pm

Maybe the current is being limited by the controller programming. You did buy this second hand right?
Get a Cycle Analyst and a Multimeter, you're still a noob if you don't have at least one of each.

Planning on posting questions or buying anything on this site? Put up your country (at minimum) on your profile. This is a worldwide forum and we haven't reached clairvoyance.

gazmunch   100 mW

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Re: Mac woes...

Post by gazmunch » May 19 2014 4:44pm

Yeah, but from an ES member that knows his stuff. It's not been altered from its original setup. Plus, it was happily kicking out 30amps constant on my previous dd motor.

amigafan2003   1 kW

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Re: Mac woes...

Post by amigafan2003 » May 19 2014 5:52pm

gazmunch wrote:No, that's not right at all. I should be getting 29mph at 48v according to the simulator, plus extra when my battery is hot of the charger. Something is definitely wrong.
What speed are you getting unloaded?

gazmunch   100 mW

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Re: Mac woes...

Post by gazmunch » May 20 2014 1:04am

No idea; my speedo is on the front wheel. What difference does it make?

It's only taking 1.5amps wot with the rear wheel off the ground. Should be about 3.5, right?

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Re: Mac woes...

Post by amigafan2003 » May 20 2014 2:03am

gazmunch wrote:No idea; my speedo is on the front wheel. What difference does it make?
Because if you're getting 28/29mph no load then 22mph loaded is about right.

I said it before, but 22mph on an 8t mac in a 24" wheel with a 48v battery is about right.

gazmunch   100 mW

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Re: Mac woes...

Post by gazmunch » May 20 2014 2:09am

It is 100% not right.

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Re: Mac woes...

Post by ebike11 » May 20 2014 4:39am

Sorry to go off topic guys, but what is the 6th hall sensor (white color), supposed to connect to? Most hall sensor connector have 5 wires not six thx!!!!

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izeman   100 GW

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Re: Mac woes...

Post by izeman » May 20 2014 4:46am

ebike11 wrote:Sorry to go off topic guys, but what is the 6th hall sensor (white color), supposed to connect to? Most hall sensor connector have 5 wires not six thx!!!!
there is nothing like a 6th hall sensor. there are 3 hall sensors, positive and negative. the white wire could be temp sensor.

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izeman   100 GW

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Re: Mac woes...

Post by izeman » May 20 2014 4:50am

gazmunch wrote:No idea; my speedo is on the front wheel. What difference does it make?
It's only taking 1.5amps wot with the rear wheel off the ground. Should be about 3.5, right?
1.5A no load is ok. why do you think that it should be 3.5A? no load speed is good for checking that you got the correct winding. load speed depends on so many variables (weight, voltage sag, amps, tire pressure, .... no load speed doesn't have those influences

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Re: Mac woes...

Post by ebike11 » May 20 2014 4:57am

izeman wrote:
ebike11 wrote:Sorry to go off topic guys, but what is the 6th hall sensor (white color), supposed to connect to? Most hall sensor connector have 5 wires not six thx!!!!
there is nothing like a 6th hall sensor. there are 3 hall sensors, positive and negative. the white wire could be temp sensor.
Ah, i thought it was because the white wire looks like a hall sensor wire and is in the same hall sensor connector between the black and red wires

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izeman   100 GW

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Re: Mac woes...

Post by izeman » May 20 2014 5:06am

ebike11 wrote:
izeman wrote:
ebike11 wrote:Sorry to go off topic guys, but what is the 6th hall sensor (white color), supposed to connect to? Most hall sensor connector have 5 wires not six thx!!!!
there is nothing like a 6th hall sensor. there are 3 hall sensors, positive and negative. the white wire could be temp sensor.
Ah, i thought it was because the white wire looks like a hall sensor wire and is in the same hall sensor connector between the black and red wires
i'm not sure what temp sensor is installed (if any) in your motor. you should check with your seller. there are different types. if it's from em3ev you can get a voltage reading from that wire, proportional to the temp. 0.5V=50°C and 1V=100°C. just check it. at room temp (22°C) it should show 0.22V. if it's a simple thermistor you can get a resistance reading proportional to the temperature.

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