Accu AVB 21700 4000mAh 30A by Avatar Controls - Vapovor
SC (Avatar) AVB 21700 Akku – 4000 mAh • 30 A • 3,7 V
4pcs Vapcell Inr 21700 Battery K40 4000mah 30a/45a 3.7v Li Ion Battery Similar As 40t/p42a Rechargeable Cell For Flashlight - Rechargeable Batteries - AliExpress