SW900 LCD

[chrisdeweyer]

I need a little help programming the controller.
I have P08 speed limit set to 100km/h, but the bike is still limiting to 48km/h. PAS is at level 5, which is maximum.
There is a P17 parameter that I can't find documentation for. When I lower the setting on P17 the no load speed of the bike increases.
Does anyone know what the P17 parameter is for, and consequences/ limitations of it.
I'm using a 48v battery 1000w drive 28a controller

Regards Chris

 

[eee291]

a 48V Battery will only spin the motor at about 48Km/h for most chinese 4 Turn hubs.

If you want higher speed you do have a few options.

1. Increase the wheel size
2. Increase Battery Voltage like to 72V or 88V
3. Terminate the phase wires into Delta
4. Get a Hub with less turns/ higher rpm/V
5. Get a 48V Controller that can do overspeed/Field weakening to get 20-30% more speed, at the cost of higher Battery drain than a normal 72V controller and Battery for the same speed.
6. I forgot what else there is.

 

[chrisdeweyer]

Thanks for your reply.
The no load speed, that's with the wheel off the ground it says it's doing about 75km/h.
The thing with the 48km/h is once I'm at that speed the motor will use less current. And if I pedal assist it will use even more less current to maintain that 48.
I have a 28inch rim with the biggest tyres that will fit the bike, to increase wheel diameter.

 

[chrisdeweyer]

What would the Kv for the Chinese 4 turn hubs?
I should be able to calculate my Max speed using Kv and wheel diameter

 

[eee291]

These numbers are for the MXUS 3000W. Other chinese 1500/3000w hubs will be pretty close to this figure.

5Tx12 or 7.2 kV = slow winding for higher efficiency at slow speeds, better recuperation, less heat development on steep hills
4Tx16 or 8.9 kV = medium winding for a medium-speed motor with good efficiency
3Tx21 or 11.9 kV = fast winding for the highest speed

 

[eee291]

http://www.ebikes.ca/tools/simulator.html

This could also help.