Textile Major Project: Equipment selection help

Hi

For my major textile project i am planning on producing a textile art free that incorporates e-textiles, I’ve been browsing the website and I’m just not 100% sure what to order. Im planning on attaching led lights to the majority of the flowers on the dress (see attached pictures). I was just wondering how strong a battery i would need, how many leds would i need, do i need multiple boards, and would the led strength become weaker the further if moves from the battery?

Thank you so much for your time
(ps. other inspiration pictures attached)
-Alisha

I was just wondering how strong a battery i would need,

Strong is not the word for the battery. You have two parameters in the battery, first is the output voltage and second is the batteries’ capacity.
Voltage is measured in volts and you will most likely have to do something electronically to match the battery to your circuit.

Capacity is measured in Amp hours, or milliamperes hour, usually abbreviated to mAh. It is used to find out how long the battery will run given any particular current drawn from it. So a 5Ah battery can produce 5 Amps for one hour or one amp for five hours. In practice take this theoretical value and half it.
See:- What Is mAh? (Milliamp Hours) | Ubergizmo

You have not given any technical information about your project, like are the LEDs just on or do you want them fading or flashing, do all the LEDs need to do the same thing or do you want individuals control of each one? Do the LEDs have to be the same colour, or different colours, or do the colours need to change?

These things are vital to give you good advice.

would the led strength become weaker the further if moves from the battery?

No.

Hi, i would like for the LEDs to be all the same colour (white), and for them to be individually fading in and out

OK so the words "individually fading" means that you have to have some sort of electronics as well as an Arduino unless you use an addressable strip.
Something like a Adafruit 16-Channel 12-bit PWM/Servo Shield - I2C interface – Pimoroni.
I know it says servo but it is the same signal as for an LED. This gives you brightness control of 16 LEDs. If you want more then use more boards.

The simplest method would be with a white addressable LED strip cut up. However there are more wires connecting the LEDs, that is three as against two with the board. You could use RGB strip and have all three colours on the same value, but that is less satisfactory.

A single white LED will not take more than 20mA and can be quite bright at currents of 5mA and less. This is good news because any battery life would be longer.

Battery capacity is measured in Amperehours (Ah) or milliAmperehours (mAh), and allows one to roughly estimate the number of hours that a battery can supply a given current.

For example, an alkaline AA cell is rated at about 2.5 Ah, which means it can supply 1 Ampere for roughly 2.5 hours, or 0.1 Amp for 25 hours, etc.

Grumpy_Mike:
Capacity is measured in Amps per hour, or milliamperes per hour, usually abreaviated to mA/H. It is used to find out how long the

It's amps times hour, not per hour, abbreviation is Ah or mAh. 2000 mAh = 2000 mA for 1 hour or 200 mA for 10 hours.

For the LEDs: why not go for WS1812b LEDs, those are pretty cheap and are individually addressable. This are RGB LEDs, so to get white the colours are mixed. Another option is the SK6812 which is an RGBW strip, adding a separate white LED for better white.

Very easy to control, all daisy chained: three wires going from LED to LED. You need just one output on the Arduino to control them all.