As I mentioned earlier, that I pulled the cells from a few power banks to make battery packs for an R/C boat. That left me with a few of the 5V USB micro in/ boost to 5V USB out - electronics.
My Miller 102 bank/charger won't take protected cells without modifying it, and even at that it is a very tight fit.
I soldered a pair of magnets to some wires, and the wires to the circuit board. This made a very minimalist charger/battery bank. I threw it into my little toiletries travel bag that I use when I travel. I also included a USB wall wart, a pair of USB/micro usb charging cables (one never knows when one of them will fail.) and a 24v/-12v car cigar lighter USB converter.