Time to add some interesting stuff here.
First of all I must admit I've been vaguely considering the purchase of some additional battery testing gadget, for affordable money of course (not in O:) a hurry). But I also like things to be good, powerful and even beautiful, so let me show you:
That looks like a lot of gadget for little money. I wonder if that can make discharge graphs, it looks like it is able or sort of.
I may be looking at the wrong :D stuff, but certainly looks interesting.
I also found quite inexpensive 16500 cells which look to be manufactured by Heter Battery: https://www.aliexpress.com/item/2pcs-lot-Free-shipping-16500-battery-1200mah-3-7V-Li-ion-rechargeable-battery-with-flat-top/32882185152.html
I have no particular interest in them but found them good candidates for a review given their price.
16500 is an odd battery format, what stuff uses this? They do fit in SK68 flashlights, but I seriously doubt they were designed with them in mind. Maybe for the small electric appliance market?
Cheers ^:)