Soco TC performance test 20220322

 I have made a watt meter with ASC758, I test my TC with original battery(60V 30AH) and original speed controller.


The result is that no matter I ran on a flat or a up hill(gear 1 or 3 does not matter), the current is controlled at 40A...with 60V it gives 2400W, when battery is fresh, the watt could be higher with higher voltage.

and when going up hill, the voltage will drop to 58V, so the power will drop as well as speed.


I believe the current limit comes from the speed controller. since BMS would not have the ability to control current at this precision.

To increase the power, few ideals:

1. increase the voltage

according to this video on utube: https://youtu.be/0xSuIvrNwVs the original controller seems also have a over voltage protection at 75 volts, once over voltaged controller will not drive the wheel, and you need to go down to 72V for the controller to drive the wheel.

original battery 17S is charged at 71V= 17S*4.17V

if we charged at 4.1V/cell, with 75V limit, we can do 18S*4.1V=73.8V, so adding a li-po cell with good capacity will do the trick. and the power increase will be about 40A*3.5V= 140W, make total power as (depends on the voltage drop)

40A *3.5V*18S= 2520W 

40A *3.7V*18S= 2664W 

40A *4.16V*18S= 3000W 

2. increase the current

the original battery is a 60V 30AH, with 40A discharge, it runs only at 1.3C, I think it could handle more than this. 

Increase the current, changing a speed controller is doable, but I want to see what is the mosfet in side the original controller, I believe we can push a little more than 40A on this. But will need very careful temperature control on controller and motor.

3. change the power wiring

the cable used from battery to controller is pretty small in diameter, and the connector on battery is reported to melt down some times. I open the battery and saw there are 10AWG with XT60 connector inside. replacing power cable from battery to controller with 10AWG seems reasonable, and re can try to decrease the total length. 

cable goes to motor after the break
cable goes to motor after the break, it's tiny...
and connector has very small contact area.
(one goes to controller, small on goes to 12V DC/DC converter)

The XT60 inside the battery and the cable is10AWG




For the section from controller to motor seems also quite long, it could be shorten if we move the controller to some where between battery and motor. I'll see this later.


Conclusion:

1. change the power wire form battery to speed controller.

2. get a cell of lipo with good capacity to boost up voltage.

3. open up speed controller to see if there is room for current limit.

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