Connect 3 li ion battery with Arduino UNO

Projects General Guidance
1

My friends and I are making a laptop-controlled car. I want to power it up with li-ion batteries because it is rechargeable. How do I connect the 3-cell battery holder I used for 3 batteries with the Arduino UNO R3 board?

2

Use only 2 batteries in series to have 7.4V and connect it negative to GND and positive to VIN

3

Connect to what?

1 Like
4

But we have other components that need more than 7.4V

5

So present your components and wiring! How can we guess, what you are trying to power?

6

What are connecting this battery pack to

7

To the Arduino UNO R3 board

8
  1. Arduino Uno:
  • Model: Arduino UNO R3 board
  1. Motors:
  • Type: 12V 20 RPM Geared DC Motor
  • Quantity: 4
  1. Motor Driver:
  • Model: L298N Dual H-Bridge Motor Driver
  1. Bluetooth Module:
  • Model: DIY Retails Robocraze Hc05 Bluetooth Transceiver Module With TTL Outputs (With Base)
  1. Camera Module:
  • Model: ESP32 CAM Lens OV2640 | Wide Angle 160 Degree | Night Vision 850nm
  1. Li-ion Battery Pack:
  • Voltage: 7.4V or 11.1V (2S or 3S configuration)
  • Capacity: As per your requirement (e.g., 2200mAh, 3000mAh)
  1. Battery Holder:
  • Type: Compatible with the chosen Li-ion cells
  1. DC-DC Converter (if needed):
  • Model: Buck converter to step down from 11.1V to 7V (if using a higher voltage battery pack)
  1. Battery Protection Circuit:
  • Model: Protection module for 2S or 3S Li-ion battery pack
  1. Wires and Connectors:
  • Various lengths and types for connections
  1. Chassis:
  • Model: Suitable for mounting the motors and battery pack
  1. Wheels:
  • Model: Compatible with the 12V DC motors
  1. Miscellaneous:
  • Screws, nuts, and bolts for assembly
  • Breadboard and jumper wires for prototyping
  • On/Off switch

To be honest it was generated by ChaTGPT cause I could not type this much but the list is correct.

9

There is your answer:
This is a good choice

10

I'm not close friend with ChatGpt, but list looks ok.
So what is your question actually?

11

So I want to connect the 3 lithium/li-ion batteries to the Arduino using a battery holder like this one: https://www.amazon.in/CentIoT-Lithium-Battery-Plastic-Retention/dp/B08DMWY4NP
So how do I connect the holder with the Arduino UNO?

12

That wasn't my question...

13

That wasn't my question...

Well if you want to connect your battery pack to your Arduino, then that is the answer.
The Polulu buck is perfect.
If that is not your question then what is it??

1 Like
14

What does the buck even do?

15

Three Li-ion batteries will have a voltage of 12.6V when fully charged and a nominal voltage of 11.1V. That is a little high for the Uno especially if you are powering things from the 5V output pin.
The buck converts the 12.6-11.1V to 9V which is safer for the Uno.

16

Will 2 batteries do the job for all my components because I don't know how to use the buck thing?

17

Will 2 batteries do the job for all my components because I don't know how to use the buck thing?

  • Type: 12V 20 RPM Geared DC Motor
  • Quantity: 4

NO.
Why are you using 12V motors?

18

To move the car that we are making.

19

Why not 3V or 5V or 6V motors?

20

It is a gear motor especially made for cars I don't know why it is 12V only but every gear motor is of 12V you can check:https://www.amazon.in/gp/product/B0C9QP4R9P/ref=ewc_pr_img_2?smid=A1KKHARUWH0JGF&psc=1