A power "platform" for Arduino Pro Mini's?

[NeverDie]

I have a number of sensor projects that sit within the nice footprint of a Pro Mini. Now I want to find a kind of universal power platform--hopefully small--to power them. So far, what I came up with was this, which runs the Pro Mini from 2xAAA batteries, and where the Pro Mini (and whatever the project built on it) simply "plugs in" to it:

Is there anything better? Ideas? Comments?

[NeverDie]

I think maybe connecting to an arbitrary power pack using a JST connector might be the easiest solution: https://www.aliexpress.com/item/100-Sets-JST-XH-2-54-2-Pin-Connector-plug-Male-and-Female-with-Crimps/32717931586.html?spm=2114.10010108.addToCart.9.69917528MGL6lj&traffic_analysisId=recommend_2049_6_99724_isgraebd&scm=1007.12908.99724.0&pvid=9f540890-4f9d-4ad0-b7df-aa0930800c7b&tpp=1

Then, just use double-sided tape to secure the Pro Mini to the power pack, and done.

[NeverDie]

I came up with some variations on the above ideas:

The three on the left are very close to the size of just 2x AAA batteries. One of the two on the right uses a JST-XH connector. The next iteration of the LoRa shield PCB will have that JST connector plugging in from the side so that it doesn't interfere with the FTDI connector as much. I think that for connecting to custom made PCB's, the JST connector doesn't actually make much sense, but it would make sense if plugging into a COT power pack.