Advice on jump starter / power bank to power NexStar

I'm considering getting a lithium car jump starter to power my NexStar mount, which takes 12v input via a 5.5x2.1mm barrel jack, central contact positive, apparently.

These jump starters basically double as power banks, some of them have a barrel 12v output connector in addition to the clamps used to start your car. This 12v output is a must, then - not every model provides it.

So I was wondering if there are any recommendations on specific models to get. Chinese shops like Aliexpress, etc. a plus, since I'm not in the US, and Amazon doesn't ship here.

Thank you.