Amazon has an external USB charger at a steep discount today.
It’s available in multiple colors and is cheaper than other external chargers I’ve bought.
From the reviews, it is important to understand the instructions in order to get it to work correctly (though the reviews seem to do a good job at translating this).
Disclaimer: I receive a small percentage of Amazon purchases and appreciate your support. Though I may donate it to George at TBB if he appears on the blog in heels.