21700 4s1p 18000mAH battery pack

Battery pack based around a cheap IP5389 bidirectional charging module and 4x 21700 batteries (I used Molicel P45B for 4500mAH each)
I made it to upgrade my heated jacket battery, double the capacity for just a hair bigger size and capable of fast charging my phone or even a laptop

This is the exact charging module I used although it's gone up in price and could probably buy it elsewhere for cheaper

18000mAH equivalent (since most battery packs are rated at 3.7v even though this is series)