Ema Stack stackable gadgets system

A while ago I had an idea to create a system of stackable gadgets that may be useful in many occasions. The idea is to have a battery pack that will have USB charger in it and contacts on top that may power other device(s). These other devices will hold using magnets. Top of the device will have contacts and magnets so more devices may be added. Those devices may be lantern/lamp, Bluetooth speaker, clock/barometer/thermometer, etc. All electronics is based on cheap widely available boards. As set will grow, I'm planning to add battery pack with built-in solar charger, possibly gesture control for lights, wifi / screen to display some information from internet, motions sensors, etc. The list may grow as far as the imagination goes.

At this moment I have finished 2 versions of battery packs - bigger one for 6 x 18650 batteries and smaller one for 6 x 18350 batteries. I also designed "bottoms" for chargers with one and two USB ports, also have tiny lantern add-on.

I use battery pack