There are two kinds of 18650 batteries: without or with built in IC (DW01) protection. I am going to test the one without protection.
Nitecore NL1835 NL835HP rechargeable battery 18650 3.6V Li-ion 3500mAh Output 2A (no built in protection) - AliExpress HK$132 (US$17)
https://www.aliexpress.com/item/1005002164902680.html
Nitecore NL1835 NL835HP rechargeable battery 18650 3.6V Li-ion 3500mAh Output 2A (no built in protection) - AliExpress HK$132 (US$17)
https://www.aliexpress.com/item/1005002164902680.html