300Wh power bank case

thingiverse

This design is for an ali express product linked below. https://www.aliexpress.com/item/1005003611042798.html Its better casing as it allows more battery storage capacity and better cooling for the buck boost supply's, Ive included a diagram of how i setup the battery's, with a BMS. Holding 20 18650 cells in sets of 4. it should hold between 200Wh and 300Wh depending on the cells you use. for printing i sliced the case into 3 parts for ease of printing. i used the standard battery's holders, and put lots of tape and card between the layers. the USB-C is 100w bi directional, so this will charge from a phone charger, or laptop charger. but also be able to power a phone and laptop. theirs a barrel jack that's got the same driving circuitry, so it can both output between 3.3v and 21v dc. as well as taking any voltage in that range as an input. To set the output voltage on the barrel jack, hold the round button for a few seconds until "VREG-DC" flashes, then use the arrow buttons to chose a voltage. once set hold the round button again to set it, before plugging in a load. for input you can just plug anything in and it will start drawing current and measuring the input voltage. Notes for use : if the power bank ever crashes or acts funny, hold the round button and Arrow key closest to the USB-C for 10 seconds, it will flash 0% and restart the micro controller in it. You MUST tap the round button before plugging in a load on the barrel jack, otherwise it kills its MOSFETs.