Hello, I have a LED battery indicator (36 volts) built into a throttle for an electric scooter. The issue is the scooter is 24 volts so i assume the indicator will not read correctly. Is there anyway to modify these components so the battery indicator would read correctly

 

Did this come with the scooter, or have you added it?

 

I added it but at the time didn’t realize that it was 36 volts and the return window has closed. The throttle portion works well but would like to get the indicator to work correctly.

 

Your indicator will show the battery voltage as 66% of the actual voltage. I would just use it as is.

 

You would need access to the voltage connection going to the indicator to change its sensitivity.
Do you have that?

 

You will need to take pictures of the inside circuit board, the voltage sensing will probably be using resistors.

 

You would need access to the voltage connection going to the indicator to change its sensitivity.
Do you have that?

Yes I have full access to the voltage connection

 

Open the indicator and take pictures.
Internally, the circuit will reduce 36V input to a suitable lower voltage range.
You need to modify the internal circuit to give less attenuation. A simple resistor change is all that is necessary. You just need to determine which resistor to change and to what value.

Edit: Dodgydave beat me to it.

 

Yes I have full access to the voltage connection

Open the indicator and take pictures.
Internally, the circuit will reduce 36V input to a suitable lower voltage range.
You need to modify the internal circuit to give less attenuation. A simple resistor change is all that is necessary. You just need to determine which resistor to change and to what value.

Edit: Dodgydave beat me to it.

Unfortunately the indicator is sealed up and looks like the only way to access it is to break it open. I have access to the power wire that is dedicated to this indicator could I put some type of resistor there? This is for my granddaughte’s scooter and she is always running out of battery so I’m hoping to come up with a fix where she would have some sort of an idea of how much remaing battery power she has left.

 

No. An external resistor will not solve the problem. You would need to amplify the incoming voltage to 150%.
I have repaired a number of devices that seemingly appear to be impossible to open. They are held together with tabs around the edges of the case. I would just try to force it open even if you end up breaking the tabs.

Your other option is just leave it alone and use it as is.

 

You would need some type of voltage boost circuit to convert the 0-24V proportionally into 0-36V and unfortunately, that's requires more than just a resistor or two.
One way would be a small 36V boost switching regulator (example), powering a circuit (such as transistor or high-voltage op amp) with a gain of 36/24 = 1.5.

 

You could try a voltage divider in reverse, I dought it needs much current.

 

You could try a voltage divider in reverse, I dought it needs much current.

Huh?

 

No. An external resistor will not solve the problem. You would need to amplify the incoming voltage to 150%.
I have repaired a number of devices that seemingly appear to be impossible to open. They are held together with tabs around the edges of the case. I would just try to force it open even if you end up breaking the tabs.

Your other option is just leave it alone and use it as is.

Fair enough I will get that open and take a photo of the circuit for the battery indicator and post it. I appreciate your time

 

You could try a voltage divider in reverse, I dought it needs much current.

In other words, an amplifier?

 

You would need some type of voltage boost circuit to convert the 0-24V proportionally into 0-36V and unfortunately, that's requires more than just a resistor or two.
One way would be a small 36V boost switching regulator (example), powering a circuit (such as transistor or high-voltage op amp) with a gain of 36/24 = 1.5.

Makes sense so if I boost the power of the lead that goes to the indicator it should read pretty close I assume.

 

To go that route, you would require an amplifier with a gain of 1.5, for example, you need to amplify 24V to 36V. In order to do that you need a power source of at least 36V, maybe 40V. Hopefully, you can see the obstacles that present here.

 

To go that route, you would require an amplifier with a gain of 1.5, for example, you need to amplify 24V to 36V. In order to do that you need a power source of at least 36V, maybe 40V. Hopefully, you can see the obstacles that present here.

Not to mention the heat in a very enclosed place. You were correct I was able to get access to the circuit board (see attached)

 

I was able to get access to the circuit board (see attached)

What are the markings on the IC package?

 

What are the markings on the IC package?