My neighbor hate me for playing loud music, so I thougt, why not make them more upset with a larger battery.

I used eight 32700 lifepo4 cells with 6000mAh for a LONG stable sound.
And to be sure that my house didn't burn down, I bought a lifepo4 4s 30a bms (battery management system)
The screen is a 7-100V battery indicator from AliExpress.

The original soundboks battery has 7,8Ah which you can play around 5 hours on max blast.
This battery has 12Ah which you can play about 9 hours on max.

To make this battery, you either need a solder iron, or a battery welder.
I welded it to be a 4s2p.

I used my upgraded Ender 3 S1 to print this, but any other printer would work.

I used:
Layer Height: 0.16mm
Infill: 100%
Speed: 200mm/s
Supports: None