Overview
This compact mini submersible pump runs on just 3V to 5V DC, making it ideal for low-power and battery projects: automatic plant watering, small fountains, aquariums, and DIY cooling. It sits fully submerged and moves water quietly through its outlet nozzle.
The pump draws more current than a microcontroller pin can supply, so you switch it with a relay or transistor from an Arduino, ESP32, or Raspberry Pi. Pair it with a soil-moisture sensor for hands-free watering.
At a Glance
Voltage
3V - 5V DC
Flow Rate
~80-100 L/H
Max Lift
~0.5-1 m
Type
Submersible
Current
~100-200 mA
Control
Relay or transistor
Specifications
| Parameter | Value |
| Operating Voltage | 3V - 5V DC |
| Operating Current | ~100 - 200 mA |
| Flow Rate | ~80 - 100 L/H |
| Maximum Lift | ~0.5 - 1 m |
| Outlet Diameter | ~7 mm |
| Motor Type | DC submersible |
| Duty | Must stay submerged in liquid |
Wiring Guide
Arduino / ESP32 Wiring
Drive the pump through a relay module or an NPN transistor / logic-level MOSFET with a flyback diode. Do not connect it directly to a GPIO pin.
| Connection | Goes To |
|---|---|
| Pump + | External 3-5V supply + |
| Pump - | Relay COM or transistor collector/drain |
| Relay IN / gate | GPIO control pin (e.g., D7) |
| Supply GND | Common ground with board |
Warning: Switch the pump with a relay or transistor, never a bare GPIO pin, and share a common ground between the supply and the board.
Tip: A 1N4007 flyback diode across the pump leads protects your transistor from voltage spikes.
Raspberry Pi Wiring
Use a relay module or MOSFET on a GPIO pin to switch an external supply. The Pi's 3.3V logic drives most relay modules directly.
| Connection | Goes To |
|---|---|
| Relay IN | GPIO17 (pin 11) |
| Relay VCC / GND | 5V and GND |
| Pump | Switched by relay on external supply |
Code Examples
Arduino
pump.ino
// Switch a 3-5V pump via relay/transistor on pin 7
const int PUMP = 7;
void setup() {
pinMode(PUMP, OUTPUT);
digitalWrite(PUMP, LOW);
}
void loop() {
digitalWrite(PUMP, HIGH); // pump ON
delay(3000);
digitalWrite(PUMP, LOW); // pump OFF
delay(30000);
}
Frequently Asked Questions
Can it run from 3 AA batteries?
Yes. Three alkaline AAs (~4.5V) work well. Switch the pump with a transistor or relay rather than wiring it through the microcontroller.
Can it run dry?
No. It must stay submerged. Running dry overheats and damages the motor within minutes.
Why is the flow weak?
Flow drops sharply with vertical lift and with lower voltage. Keep the outlet low and supply a steady 5V for maximum output.
Do I need a flyback diode?
Yes when using a bare transistor or MOSFET. A 1N4007 across the pump leads absorbs the inductive spike. Protected relay modules handle it for you.
How do I automate watering?
Read a capacitive soil-moisture sensor and turn the pump on when the soil is dry, off when moist. Add a maximum run time as a safety limit.