Best option to balance charge a 4S5P DIY li-ion pack

[Ozzyfr]

Hi,

I am looking at the best option to protect and balance charge a 4S5P battery pack I built myself.
I know a BMS is not a charge controller and I cannot use an Imax B6 external, it has to be a simple and very basic power supply.
I can't use 4 TP4056 as they share the same ground, I can use a BMS to protect against shorts and over discharge and i was thinking of mixing it with a charge controller to balance charge correctly but I can't find any good reference.

Can anyone help me find the best way to build this pack?
Thank you very much