USB Power Delivery is just flat out great. You get various voltages including 5, 7.5, 9, 12, 15, or 20V up to 5A. I have converted a load of stuff to run on US

USB Power Delivery is just flat out great. You get various voltages including 5, 7.5, 9, 12, 15, or 20V up to 5A. I have converted a load of stuff to run on USB-C PD. My most useful one is a travel CPAP. It consists of a USB PD trigger and a boost converter to step 20V to 24V. The trigger board is integrated into the USB-C connector and there is a small 3d printed box for the boost converter inline to contain it and provide space to adapt the output to the proprietary DC connector. Anyone wanting to DIY something similar can find PD triggers or PD trigger cables on aliexpress or ebay easily. There are tons of products right now on Amazon and elsewhere that are basically nothing more than USB-C PD input, DC barrel plug output. Super useful, especially paired with a compatible power bank. Unfortunately for some reason all the suppliers set them at 20v despite the ICs they use in them being able to request a different voltage.