how long can the pedal go without being charged after full.charge

ATTenTion: Many folks who answered your query in "[How many hours will the pedal hold a charge]" got variations, extrapolations. all w good intent. "Nope. I've never seen or heard of an effects pedal that is chargeable and this pedal doesn't change that”. You must access power AS you use it. There are essentially two ways to get to your juice. 1)Plug in a ac/dc adapter from wall to your Azor. OR 2) A 9 volt adapter from our favorite store. What don't they have ? Amazon, as of 8/20/22, has an adapter for a 9 volt battery that fits our delay--by-pass pedal from Azor. The battery lays, on the side if you like, un-noticed-a non-distraction. **Pick up a pack of 9 volt batteries if you're going the DC route. I have the ac/dc adapter & 9volt adapter. Freedom. sweet Freedom. No negotiating for plug in 'priviledges' When busking, its always someone who "lords over it". The 'spot'-- quality traffic & Power. It, delay, doesn't have a compartment w/i the metal housing to attach the 9 volt battery

Can you put a 9-volt battery in it?

It seems to me that the question is simple. The answer is NO. Larger effects pedals take an internal PP3 9V battery. This is a mini-effects pedal and (as per your question) NO, you CANNOT put a 9V battery in it. You can however use an external 9V battery or 9V PSU.