hello makers, new to Picobricks, looking for a solution to power it

Hello everyone, hope you have a good day,

I'm creating a projet and I need to use the Pico and some picobricks components outside, without USB powering then. I tested with the default battery compartment (3v) but it doesn't seem to work. However, powering with a phone powerbank via a USB cable work, but it's too big and heavy.

I'm wondering if there are any other solutions, and how to apply them.

Thx for reading,

t0qen

PS: here is a photo of my project

PS 2: I'm french, be friendly about my writing, please