8Fun 48V500W = 34kph?? no load

[ebike11]

Hi guys
Just went out and got myself a new 48v500w code12 Bafang/8fun motor/wheel.
I paired it up with my new fully charged 48v10ah li-ion battery. My bike is a 26" MTB.
I upended the bike during installation and open the throttle wide open. Max. speed was 34kph
with the wheel freely spinning and rear disc hub/caliper not attached.

I was expecting a little higher kph considering it wasnt road speed. Controller is ku93 with speed limiter
disabled. Hall sensors and phase wires are connected correctly according to color.

There isnt any problem or weird noises etc, just was expecting a tad higher. Cycle computer is connected
properly as well.

Should I swap around the phase and/or hall sensor wires to see if anything is hampering
higher speeds?? Or something else I could try?

Thanks in advance!!!

Thanks

 

[lotrwiz]

How odd, I get that speed from my 36v 250w bafang :O

 

[docnjoj]

Hi guys
Just went out and got myself a new 48v500w code12 Bafang/8fun motor/wheel.
I paired it up with my new fully charged 48v10ah li-ion battery. My bike is a 26" MTB.
I upended the bike during installation and open the throttle wide open. Max. speed was 34kph

with the wheel freely spinning and rear disc hub/caliper not attached.

You should have a Wattmeter attached so you can see Amp draw. Most motors will be around 1-2 amps, geared motors a bit higher but not much.
otherDoc

 

[docnjoj]

Connect the Wattmeter between the battery and the controller.
otherDoc

 

[ebike11]

So after determining the amp draw, and if its high, then what does that mean or suggest that I should adjust???
Thx

 

[d8veh]

The KU93 has fully automatic phase sequence and angle detection. Just connect the motor wires colour to colour and the controller will figure out the rest. Your speed is correct, anyway..

Code 12 is 250 rpm, so no load speed should be 31 km/h at 48v or 34 km/hr with your 48v battery at it's average 53v.Fully charged, it'll go a bit faster,

You can get a reasonable speed boost if you have the hall sensors connected by using the three-speed switch connector. Connect the middle black wire to one of the other two, and it will either go a lot slower or a bit faster. connecting the middle to the other outer one is the other way round, so find out which one gives the boost, and run it to a switch on the handlebars.To test it, you only have to bridge it with a short piece of wire. It changes the timing somehow to get the motor to run over-speed, but it won't work very well at low speed, which is why you need the switch. The speed boost doesn't work if you're running sensorless.

 

[ebike11]

Ok thanks for the info,
Now the ku93 is a 20A controller. Would I see any difference with
the exact same set up but with a 30A controller?

 

[ebike11]

@d8veh,

do you mean, to get speed boost, connect the "green" wire to either the left or right wire??
My hall sensor connector looks like this:

Black empty Red
Blue Green Yellow

 

[brumbrum]

Hi mate, we have gone through all this via pm's.
You need a higher rpm motor for higher speed say...400rpm when loaded such as a Mac 6T and you need a controller that will do more than 20 amps, say 30/35 to get up to 30 mph, i think this is what you were after.... iirc?

You must test the amp draw when the motor is off the ground with a watt meter connect between controller and battery. Slowly pull the throtlle and the amps should stay under 4 amp usually more like 2 or 3 amps. I use a cheap chinese one.... http://www.ebay.co.uk/itm/171123750032?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

It it rises a above this amount try swapping around the phase and hall wires until it is under 4 amps and motor makes no rattling or unusual noises.

If you want to go on codes rather than rpms you need a low code motor for faster speeds.

Remember that the rpm cannot be changed that much to what it is rated for. Here are all 36 differing wiring combinations for phase and hall wires being connected together. If you have not gone through this process you are not a real ebike hobbyist :wink: .... http://www24.brinkster.com/lyen/product/controller/Sensored_Combination_Worksheet_V2.htm


By the way, i have a code 15 216rpm 500w BPM and it only does 18-20mph tops on a 54v lithium ion sony pack. Set at 25 amps to conserve battery capacity.




Andrew.

@d8veh,

do you mean, to get speed boost, connect the "green" wire to either the left or right wire??
My hall sensor connector looks like this:

Black empty Red
Blue Green Yellow

 

[brumbrum]

How odd, I get that speed from my 36v 250w bafang :O

But i bet he could kit your arse off the line :lol:

 

[d8veh]

Ok thanks for the info,
Now the ku93 is a 20A controller. Would I see any difference with
the exact same set up but with a 30A controller?

No. A 30A controller will just get you to 34km/h quicker.

@d8veh,

do you mean, to get speed boost, connect the "green" wire to either the left or right wire??
My hall sensor connector looks like this:

Black empty Red
Blue Green Yellow

That's the hall sensor connector that has to be connected to the motor.
The three speed switch connector has blue, black, green. You connect the black to the green IIRC, but it might be black to blue.

 

[brumbrum]

http://www.bmsbattery.com/ebike-parts/53-three-speed-switch-kit.html

this is compatiblae with your controller. if it does not work , try swapping the wires around as d8veh has said.