Last year I bought a Raspberry Pi 3B+, which has become the basis of a digital jukebox with 10,000 music tracks.
The portable jukebox, has the following components:
• Dell Laptop 19.5V 4.62A battery charger (indoors)
• 2 x ALDI 2Ah Xfinity Plus 20V rechargeable battery packs plus ALDI battery recharger
• Australian Telecom 605 Telephone plug (this slides directly into the ALDI battery packs (with the central lug removed)
• TPA3116 D2 Dual Channel Class D Digital Amplifier Board (for the audio side), this will accept any voltage from 15 to 24V.
• Buck converter: This draws some of the power from the Dell Laptop charger (or batteries), reducing it to 5.2V for the Raspberry Pi (comfortably above the 5 volts required but not high enough to fry the Pi.
• Raspberry Pi Model 3B+ with added heat sink on the CPU
• 5 inch 800 x 480 HDMI touch screen monitor
• 2 x 3 inch LG 8ohm speaker drivers rescued from a couple of LG home theatre towers.
• On/Off switch for power
• Volume control knob for the digital amplifier
• 2 x asymmetrical hand-made speaker cases, painted in hammer finish paint with solid brass carry handles, and speaker mesh guards.
• Cordless Bluetooth micro keyboard and mouse (plus stylus for the touch screen.
• 32GB SD Card containing Raspbian Stretch O.S.
• 128GB USB 3.1 Stick with 10,000 music tracks (70GB) mainly MP3, some other formats.
Software: Chromium Web browser
Clementine Music Management suite to play music from the library and access several thousand streaming radio stations
Videolan VLC for watching YouTube clips
I stress tested the device, playing internet radio for 48 hours non-stop, whilst running a number of Linux-based CPU stress tests.
The second speaker is attached via a long lead to enable stereo sound separation.
It boots in 23.8 seconds and the amp has plenty of oomph, my crockery rattles when I crank up the volume.
Components assembled from top right (clockwise): Class D Digital amplifier; switches and external plugs; Buck converter, RPi piggybacked on 5inch screen.
Completed unit with Dell power supply, Bluetooth mouse and keyboard.
External power supply (4-5 hours per battery): ALDI Xfinity 20V Li-Ion battery pack with modified Australian Telelecom 605 Phone plug.
NB: Once the middle lug is snipped off, the telephone plug slides perfectly In the battery pack.