What is inside the throttle?

[GM Brazil]

My throttle does not shows correctly the low battery status. The battery is a GM 48V12Ah, and the throttle is the 48v one, but when the BMS cuts off the battery the leds still showing that it is at half, and not low.

Is there some way to modify the throttle leds so it shows the correct low voltage information?

Thanks!

****** Check out this post for a simple solution******

[Micha]

I just replaced the thumb throttle that came with the Pro Kit 902 for a thumb throttle that doesn't have the led's, as the "inaccurate" led readings annoy me and I don't like the design at all with that large led block on top.

Bought a throttle like the throttle pictured:


The thing is that the new throttle is only responsive over a smaller range than it's total rotation from closed to fully open.

Let's say closed is 0% throttle, and open is 100% of the rotation.
This throttle only responds from 20%-60% of the rotation, but still enabeling with 0-100% throttle.

What is causing this, and can I do something about this?

[Bikemad]

The throttle output signal is affected by three main factors (assuming the +5V supply is always a constant 5V):

• The sensitivity of the hall sensor
• The strength of the magnets
• The proximity of the magnetic poles in relation to the sensor

Unfortunately, none of the above can be altered easily.

However, it should be possible to fine tune the operation of the throttle, but you would need to use a pair of 10k Ohms trim pot resistors to adjust the voltage at the +5V and 0V inputs of the hall sensor.



Make sure the two resistors are pre-adjusted so the least resistance (ideally 0 Ohms) is between the two pins with the same colour wire (2 and 3 in the diagram) before you connect any power, as there's a good chance that it could actually supply the hall sensor with a reverse polarity feed if they were both accidentally adjusted the wrong way!

Reducing the +5V supply to the throttle should reduce the unresponsive 60-100% portion of the throttle movement and increasing the 0V supply should reduce the unused 0-20% portion of the throttle movement.

Adjusting the lower end setting will have a slight effect on the higher end setting (and vice versa) so it may take a little bit of trial and error to get it adjusted just right.

Unfortunately, if the output from the 0V resistor is set too high, you may find that the power on safety feature of the controller will prevent the motor from running. 

Alan
 
EDIT:
The vector controllers seem to have a different usable throttle range according to the battery voltage being used.
This would mean that the resistors would need to be readjusted if you changed the battery voltage setting in the controller.

[Micha]

Thanks Alan,

Will see if I can do something about point 2,3 before I venture into relatively unknown territory you opted with the resistors