Powering Arduino nano, 128x32 oled display, and sg90 servo motor

Projects General Guidance
1

Hi there,
I have a Project consist of arduino nano, 128x32 oled display, and sg90 servo motor and I want a sustainable powering solution for them. let's say the servo motor will sweep 20 times a day and the display with the arduino will be on for like 5 to 10 hours per day.
should I use rechargable batteries to power this Project? if so, what the specifications of these batteries should be and how to connect them (like servo and arduino powering will be separate). Or is it enough to use 1.5V or 9V batteries to last for like a month of consuming. is there other suitable suggestion?

2

Reading the datasheets for the devices You'll note the current they draw. Multiply that with the number of hours You want to run the setup. There's the capacity You need.

3

Welcome to the forum.

Let's say 50mA for the Nano and 100mA for the OLED and a peak current of 500mA for the servo motor.

50mA * 24hours + 100mA * 10hours + 500mA * 1minute = 2.2 Ah per day.
For a month, you need a 5V power bank of 66 Ah.
With a car battery and a DC/DC-converter, it will last longer than a month.

A 9V battery will not last one hour, more likely a minute or less.
You need a 10kg car battery with a DC/DC-converter.

I put the picture here to show how much more you need than a 9V battery. When you are used to the idea, then we can try to lower the current usage.
If you use sleep mode and a different Arduino board and minimize the pixels that are turned on and with a good quality small servo motor, then you might be able to drop the current usage by maybe 90%.
The Arduino MKR Zero has a connector for a battery and also Adafruit has boards with a battery connector.

4

I ran one-meter length of white, COB LEDs for two weeks (24 hours/day) that were plugged into the 5V/USB port connected to a broken 15S3P ebike battery (manufactured for 10Ah, load-tested and rechargeable only to 5Ah, so considered dead, now it's my "off grid" power pack). You can find batteries at scooter/e-bike repair shop with "warrantied" batteries (not negligently damaged) that they must pay a service to discard per unit.