XT-20000QC2 Power Bank – modern DC/USB QC2 battery with 20400mAh – 1x USB, 1x USB QC 2.0 and DC connection of 12V, 16.5V, 19V, 20V and 24V 65W max.

On my boat I like this portable battery  as it outputs 12-24v and USB and charges from both as well, it will charge slowly off a small USB solar panel and fast off a full size 12v one. Hasn’t broken yet 😉

USB with a fast charger and a good cable charging is up to 15w with normal 5w and a bad cable 2.5w

From a 12-24v source charging is up to 30w