I don’t carry anything with my Kindle, just the Kindle in its cover. I do have a multi port charger block and some cables that I carry in my purse, but that’s for several electronics that I carry. The Oasis battery lasts a very long time and I take short trips so I just make sure it’s charged before I go.
A real honest long lasting battery? My iPad Mini 4 battery is getting weaker and weaker. *sigh* And I've had incidents where my iPad battery will last for days, and then occasionally, will barely last a day. No idea what happens when that happens, and it's annoying, but I end up taking chargers and cables and cases and docks and long cables and short cables and even a small wifi (Apple Express) JIC...
I did give up taking my MacBooks. Thinking maybe I should rethink that maybe. I don't know... I've spent too much money on tech this year. This pandemic is killing me...