Power misunderstanding?

Thanks for your swift replies. I'll give the 4 AA configuration a try before switching to a USB powerbank.

My need is quite simple: I need to short a circuit three times per hour, during 3 seconds each time. The functional need is to simulate the press of a button on my doorbell at given times - what the physical button actually does can be simulated by placing a wire between two pins. I succeeded in doing this with the aforementioned setup powered by USB...

Thanks a lot