Nice portable medium sized amplifier that can be ran off of several c-sized batteries unfortunately that is also why that facet of it is untested is that we are currently depleted on inventory of that battery. Otherwise those test good with the power supply, honestly this would be epic with a power tool battery conversion for extra longevity of the charge. Further questions or concerns feel free to ask, comes as photographed sold as is please see the photos to judge the condition for yourself. This does work with the functions that are presented on top that were testable with the input, keep in mind that this is being sold as shown. Thank you for looking. Charger stored inside while being photographed.