LcD Display

[saneagle]

Think i figured it out. Altered some settings. I have the pedal sensor working intermittantly. Think i need a reset and count the magnets in the motor like saneagle suggested

The motor magnets setting doesn't stop anything from working, even if you have it wildly wrong.

 

[Garry Hallam]

The motor magnets setting doesn't stop anything from working, even if you have it wildly wrong.

I think it was a combination of a few settings but seems just fine now. Thanks all

 

[Garry Hallam]

What Cable do I need to transfer settings from lcd4 to 880 controller?

 

[saneagle]

What Cable do I need to transfer settings from lcd4 to 880 controller?

You need to make a special cable shown on the last page of the manual, and it depends which connectors you have on your devices. All it is is a 5-way cable with the green and yellow (Tx and Rx) swapped over from one end to the other and two wires spliced in to provide power (black and red):

https://download.elecycles.com/manual/Display-Manual/LCD3-display.pdf

 

[Garry Hallam]

I have had the bike running but cannot get it to save the maximum speed setting.

The procedure I followed was:
1 Power on
2 hold up/down simultaniously
3 change speed to 15
4 change wheel to 27.5
5 change units to mph

I then press power button once. It says hold down arrow again to enter units 0,1,2,3.

Holding it down does nothing?

Holding power button returns to main screen but max speed not saved.

Very confusing. Had no problem with mid drive kits

 

[saneagle]

I have had the bike running but cannot get it to save the maximum speed setting.

The procedure I followed was:
1 Power on
2 hold up/down simultaniously
3 change speed to 15
4 change wheel to 27.5
5 change units to mph

I then press power button once. It says hold down arrow again to enter units 0,1,2,3.

Holding it down does nothing?

Holding power button returns to main screen but max speed not saved.

Very confusing. Had no problem with mid drive kits

Often, it's press and hold the two buttons to save the settings. That's how a KT controller works, anyway, which is a massive advantage for those that don't care about laws because if you set the speed limit, but don't save it, It'll keep the setting until you switch off, then revert to the previous setting, which gives a temporary undetectable higher speed setting.

 

[Garry Hallam]

I think I may have saved the settings.

Unable to road test at the moment but spinning the crank indoors gets up to 26mph.
I guess without any resistance this is normal?

 

[saneagle]

I think I may have saved the settings.

Unable to road test at the moment but spinning the crank indoors gets up to 26mph.
I guess without any resistance this is normal?

The speed with the wheel off the ground depends on the motor constant (Kv). When the motor spins it becomes a generator. The voltage it generates is opposite to the battery voltage and is equal to RPM x Kv. When the motor reaches a certain RPM the net voltage is no longer enough to push the controller's maximum current through the motor, so power decreases from that point and eventually reaches zero when RPM x KV = battery voltage, since the net voltage is zero, so no current can flow.

Every motor has a different Kv, which depends mainly on how many turns of wire there are around each pole in the stator. Because of this effect, motors reach maximum power around 75% of their maximum speed and maximum efficiency at around 80% of max speed, so you choose a motor that has a maximum RPM of about 1.3 times what you expect your modal powered riding speed to be.

For a 26" wheel, that would be around 260 rpm for 15 mph and 330 rpm for 20 mph.

The speed of any motor will increase in proportion to the battery voltage, so a 36v motor will run 30% faster at 48v (10S vs 13S). Likewise the motor's max speed when the battery is nearly empty will be about 75% of what it is when the battery's full (3.1v vs 4.2v per cell).

 

[Garry Hallam]

The speed with the wheel off the ground depends on the motor constant (Kv). When the motor spins it becomes a generator. The voltage it generates is opposite to the battery voltage and is equal to RPM x Kv. When the motor reaches a certain RPM the net voltage is no longer enough to push the controller's maximum current through the motor, so power decreases from that point and eventually reaches zero when RPM x KV = battery voltage, since the net voltage is zero, so no current can flow.

Every motor has a different Kv, which depends mainly on how many turns of wire there are around each pole in the stator. Because of this effect, motors reach maximum power around 75% of their maximum speed and maximum efficiency at around 80% of max speed, so you choose a motor that has a maximum RPM of about 1.3 times what you expect your modal powered riding speed to be.

For a 26" wheel, that would be around 260 rpm for 15 mph and 330 rpm for 20 mph.

The speed of any motor will increase in proportion to the battery voltage, so a 36v motor will run 30% faster at 48v (10S vs 13S). Likewise the motor's max speed when the battery is nearly empty will be about 75% of what it is when the battery's full (3.1v vs 4.2v per cell).

Oh Heck!
The police are checking Ebikes around here at the moment. I guess the only way round it is to repurpose the motor to another bike or use a 24v battery.

I wonder if my speed calculation was off and it is indeed intended for a 20" as the ebay seller advertised!

 

[saneagle]

Oh Heck!
The police are checking Ebikes around here at the moment. I guess the only way round it is to repurpose the motor to another bike or use a 24v battery.

I wonder if my speed calculation was off and it is indeed intended for a 20" as the ebay seller advertised!

You can set the speed limit in the LCD settings. I was talking about the natural unrestricted motor speed. My one does about 26 mph, but is fine when restricted to 15 mph.

 

[Garry Hallam]

You can set the speed limit in the LCD settings. I was talking about the natural unrestricted motor speed. My one does about 26 mph, but is fine when restricted to 15 mph.

Oh great lets hope I have saved the settings correctly. It dries up later so maybe get the chance to test it again.

 

[saneagle]

Oh great lets hope I have saved the settings correctly. It dries up later so maybe get the chance to test it again.

Here's a hint. The speed displayed comes from the speed sensor. It uses a calculation of pulse rate, number of magnets that cause a pulse per revolution and the wheel size setting. The actual speed limit is determined independent from that from a calculation based on the pulses the hall sensors make from the magnets in the motor, the reduction ratio and the wheel size.

In other words the limit speed won't be the same as the displayed speed unless you make it so. The best way to get them the same is to measure your actual speed with some phone app, then adjust the P1 number up or down until the two are the same.