I was in Jay$%^ earlier today and decided to buy a Battery Bank - 15600 MAh with 2 x USB 2.0 at 2.4 Amps and 1 x USB 3.0 at 3 Amps. Fortunately, I had a male-to-male USB C cable on hand so I can run my Pi4 8GB off that and get several hours of service before a recharge so it will be more than adequate for a night's imaging with Astroberry. I hope. Famous last words are always lurking in the background but I am hopeful it will work.
https://www.jaycar.com.au/15-600mah-...ports/p/MB3806