Luckily the battery did not explode because
Probably the charging ic or the pmic ic sacrifice itself before blowing up the battery

interesting connector for a pool water filter. I'm sure no one lost the original cord and used a line voltage cord

So I made this 3S Balance charger that uses three TP4056 modules and three 230VAC to 5V DC modules so that they can work together and charge eatch string of cells individually, this makes it so that every time you charge your battery you make sure that it will be balanced once fully charged and no cells can stop charging before they are fully charged like with a normal chargers. And the best part is this is scaleable to how many strings you want even a 100s1p pack. Every module have to have an personal galvanically isolated power source so if you don't have 5V power supplies you can use three phone adapters instead using the usb port. It's very important that the power supplies are isolated from eatch other, you can't use one power source for all three modules. I don't remember exactly why but if i am not mistaken the GND is chared by the input and output making it impossible to series connect the output if you parallel the input making a shortcurcuit.