Does anyone know how limited charging works with balancing? As I understand balancing only happens when batteries reach their full capacity. A bit of backgroun

Does anyone know how limited charging works with balancing? As I understand balancing only happens when batteries reach their full capacity. A bit of background: Batteries are made up of cells which have ever so slightly different voltages. If you have three 3.7v cells in series to make a 9.2V some cells will be 3.68V and another could be 3.72V. This is bad, because when you charge the battery it is charged as a whole unit - the BMS will simply stop charging when it reaches 9.2V (or whatever it is set to). Over time the difference between the cells will increase, which could ends up with one cell being 3.9V and another 3.5V. tThis will result in you damaging the higher cells (which if overcharged enough could cause a fire) and the lower cells will not be fully charged so the battery will have a lower capacity. My understanding: Balancing is designed to fix this. The idea is that there is a resistor in series with each cell, and it turns on when that cell reaches the set point, e.g. 3.70V. That way when you charge the battery as a whole to 9.2V, you know each individual cell is also 3.70V. This is a naive solution though, as for larger batteries you will have cells in parallel and you can't use this approach there. The better approach would be to charge each cell individually, but as I understand even large batteries like Powerwalls do not do this.