Continuing on the hijack - Eventually you will need/benefit from having an external power supply to run your avionics etc., be it for testing stuff, doing software updates in the hanger, learning how to use avionics features, sitting there making believe you are flying, etc. So, might as well get one sooner than later...
I installed a connector at the bottom of my panel where I plug in my external power supply. Mine is 20A/12V, a switching power supply that is super efficient and small and economical, a Meanwell SP-240-12. They run about $77. At 20A you can probably run all of your avionics, cycle flaps, turn on lights, etc.
These are available many places, but from DigiKey, its is on this page:
https://www.digikey.com/en/products...QRLhJUkAtngYQgDueFhYAASsxN18fTjlrKxYAng4zOJAA