Include a 9V battery pack for plug-less installation.

9v USB Rechargeable Smart Batteries

Addicore 9V Battery Cable and Barrel Plug

9V Battery Eliminator Kit

D'Addario 9 Volt Battery Power Adapter

Battery Size: 9V , Connection Type: 6

9V Battery Holder with Switch and Leads

What type of battery pack can power a device with 9V 0.5A output?

Rechargeable Battery Pack for Strat® - shop-fishman

Fishman Universal Rechargeable Battery Pack

Philmore BH139, 9V Battery Snap, 6 Lead, 26AWG Parallel, 2pk

12V, 9Ah LFP Battery (PVC, BLF-1209A)

Provides a handy way to connect a 9V battery to a project for portable operation.

9V Battery to DC Plug Adapter Cable