Run micro diaphgram pump on 3.7V Lithium Ion battery

Hey guys--

I have a project working when plugged into my PC via USB but when I try to add a 3.7V 2000mAh Lithium ion battery with a step up converter and tp4056 module the arduino board is on but the motor itself will not run. I am wondering if I need a battery with higher voltage or if my code or schematic/layout is incorrect.

Basically, when the push button is pressed the diaphragm pump runs and there is a 10k potentiometer to adjust the voltage.

Here is the schematic:

And this is what I am trying to add to the circuit:

I connect the battery to the ground and Vin on the arduino or breadboard. The board has a green and orange light on like always and I added an LED that changes when the potentiometer is twisted and that works. However, the motor still will not run. It is a cheap diaphragm pump from china and I couldnt find any SDS or data on it except for what was on the site. It should be 5V-6V though.

If I were to replace the battery (rechargeable), I cannot find an IC charging module for anything other than Lithium ion battery. Also, the size of the battery packs I see are to large so I am not to sure what to do.
Any help is appreciated. Thanks!

int analogInPin = A0;

int transistorPin = 3;

int sensorValue = 0;

nt outputValue = 0;

int switch1 = 11;

int switch2 = 10;

void setup()



pinMode(8, OUTPUT);

pinMode(9, OUTPUT);

pinMode(transistorPin, OUTPUT);

pinMode(switch1, INPUT_PULLUP);


void loop()
{int val1 = digitalRead(switch1);
int val2 = digitalRead(switch2);
sensorValue = analogRead(analogInPin)/4;
outputValue = map(sensorValue, 0, 1023, 0, 255);
if (val1 == LOW)
analogWrite(transistorPin, 0);}


analogWrite(transistorPin, sensorValue);}


What are the actual, operating, voltages on the Arduino and on the motor when you push the button?

Please post proper wiring digarams. Fritzings are wall decorations popular among sales people but not among engineers.

Please read the topic telling how to use this Forum, how to post code.
One advise is: don't buy stuff that has no data sheet unless You already know how to use it.

hi Paul
sorry for the late response. via USB, the voltage of the arduino is around 4.60 when the button is pressed and the motor reads at 3.3V when the potentiometer is turned all the way. When just the lithium ion battery is connected, the reading on the arduino is 3.7V (looks like the step up converter is not working) and when the button is pressed the motor reads 0.10V. Thanks for the help!

Thanks for the suggestions. I will make those changes. And in the future, I will definitely be more careful about what I purchase.

Check the specifications for the step up converter and read through eventual application notes.

Good Morning Railroader--

I checked and it seems the step up converter may be to weak.
1.5V 1.8V 2.5V 3V 3.7V 4.2V 5V to 3.3VDC-DC boost converter module
Input voltage 0.8-3.3V, output voltage 3.3V
Large output current: 500 mA
Starting voltage 0.8V, output current 10MA
Input 1-1.5V, output 3.3V 50-110MA
Input 1.5-2V, output 3.3V 110-160MA
Input 2-3V, output 3.3V 160-400MA
Input more than 3V, output 5V 400-500MA

is what it it is rated at. When i test the current on the running motor, it is 1800MA.
Does this mean I should get a step up converter that will output higher current?

Can you check your numbers again. If your motor is really drawing 1.8A (1800mA) then it is a miracle if it runs on USB power from a PC which can usually only supply around 0.5A.

Oh and running high currents like that through a breadboard will also cause problems. They have only low current connections.


Hi steve

you are right, it was 0.17mA, thanks for noticing that.

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