Hi
I using a BMS 3 cell for Li-Batteries like following image. To charging the batteries can I use a general 12.6VDC adapter or I need a special battery charger? I ask this because BMS modules manages the current of charge and discharging!
Another question is on the internet writes current to charge batteries should be 10% of them capacity to increase battery life span. My batteries are 2200mAh so charge current should be 220mA, but when I charging them by a lab power supply with 12.6V the current goes until about 1.8 Amp in CV mode! I limit the current down to 220mA. Why BMS not limits the current?
Thanks

 

Why BMS not limits the current?

Because the BMS has no way of knowing that your battery has a capacity of 2200mAh.

 

Because the BMS has no way of knowing that your battery has a capacity of 2200mAh.

so battery chargers also do not know the battery capacity too!

 

Unless the battery capacity information is somehow provided to a system, determining battery capacity experimentally is a complex process.

 

so chargers like this damages batteries?!

 

I asked ChatGPT, it says charge current should be 0.5C or 1C at max. So I can charge my batts with 1Amp!

 

You need a reliable constant current supply. It needs to provide ~4.2V/cell and no more than the maximum current you want to charge the cells with. While it is not a fast charge, ≤1A/cell will prolong battery life and reduce (not eliminate) the hazards associated with thermal runaway fires caused by ovewrheating during charging.

Li-Ion cells use a CC/CV charging strategy. The Constant Current phase is the first part, where voltage is limited whatever corresponds to your chosen charge current. As the battery charges, its resistance will increase and the charge voltage will rise to a maintain the target current.

At some point, the battery voltage will reach the point that more than 4.2V/cell is needed to maintain the current target and then the Constant Voltage phase takes over. The charger will hold the voltage at 4.2V and the current will reduce until the battery is at 4.2V/cell. This is is where the BMS will cut off the charging to protect the cells.

 

As the battery charges, its resistance will increase

It's voltage will rise, but I don't think its resistance increases.
Generally it's the opposite.

 

It will take longer to charge but you could use a series resistor to limit the charge current.
The charge current will then taper off as the voltage rises to the desired charge voltage.

 

It's voltage will rise, but I don't think its resistance increases.
Generally it's the opposite.

It's effective resistance. If the higher voltage is required to make the equivalent current than R must have increased.

 

You could use hat supply with an additional circuit to control and regulate the current, like "Y" described in post #7!!
Wishing the results were different will not make it so. That is the "Jim Moore Syndrome", which is sometimes fatal.