Where I live, this is actually extremely common now - typically referred to as a "Mini DC UPS" [1]. These cheaper ones just provide 9V and 12V output to power

Where I live, this is actually extremely common now - typically referred to as a "Mini DC UPS" [1]. These cheaper ones just provide 9V and 12V output to power a fibre and/or WiFi router, as well as 5V USB-A, and start at around 30Wh capacity - some for less than USD 20. If you pay a little more, you can get 24/48V PoE included as well. Unfortunately, ones providing USB-PD are quite rare. You do get "power stations" [2] with USB-PD (in addition to an AC inverter). These are typically USD 100 - USD 1000, and have much larger capacity. Examples (I haven't tested these and do not specifically recommend them): [1]: https://www.amazon.com/Lithium-Battery-Appliance-Monitor-uninterrupted/dp/B0B6FBLSB4 https://www.amazon.com/Lithium-Battery-Appliance-Monitor-uni... [2]: https://www.amazon.com/Portable-Solar-Panel-Power-Station-Generator-Charger/dp/B08G1KB88B/ref=sr_1_1?keywords=power+station&qid=1690966391&sr=8-1&ufe=app_do%3Aamzn1.fos.006c50ae-5d4c-4777-9bc0-4513d670b6bc https://www.amazon.com/Portable-Solar-Panel-Power-Station-Ge...