Vapcell S4 Plus is the best priced / performance charger at the moment. Choosing Vapcell S4 Plus is to choose peace of mind and safety.
I bought four S4 Plus chargers , because the slots are long enough to handle extra long protected usb Imalent and Nightcore 21700 batteries.
How many rooms in my building have flashlights, and how many flashlights per room? This question applies to me, but also with lithium ion battery chargers. I have two 8 bay chargers for 8 x 18650 batteries, but do they supply a total of 4 amps, one half amp per 18650 cell?
So, I use two S4 Plus chargers for 8 x18650, and I can get one half amp to each cell. Upstairs, and downstairs, in the main meeting room, and in my crash pad room, and in my office, etc. Lots of flashlights. Lots of S4 Plus chargers.
My lights: https://budgetlightforum.com/t/-/9150/287