4pcs of Li-ion LIR2450 Rechargeable Button Batteries, 2450 Coin Cells, with Charger

this is a rechargeable lir 2450 battery kit it comes with four rechargeable coin cell batteries and a charger to charge four at a time so let's open it up and see what's inside now the purpose of this is to replace the batteries in our home automation system like smart things sensors that use two 450 coin cell size batteries these rechargeable batteries won't have the same capacity as the non-rechargeable batteries they're about a quarter of the capacity which means they'll last about a quarter as long however you can you can easily recharge them and you won't have to buy new batteries all the time you can just recharge these batteries and replace them the charger itself is a usb powered charger comes with a usb cable has a micro usb connector here so kind of a ubiquitous cable you plug this in into a usb 5 volt outlet to charge it and i guess the only the only trick thing here here is