I am trying to implement passive cell balancing with using external discharge circuit. As I read the datasheet of LTC6812-1 we need to configure DCC bit for the cell we want to discharge.
I looked into the configuration register group A and B, and I noticed we have DCC0 to DCC15. However, we are monitoring only 15 cells with this LTC6812-1. why we have 16 DCC bits?
If I want to discharge cell1, should I set DCC0 or DCC1?
I also have one more question. In my discharge circuit, I am using 20 ohm resistor in the discharge path. But the discharge current for me is too small. It is around 1mA. What can be the reason for it?
Thank you for your help in advance.
As described in memory bit description table. DCC0 is for controlling GPIO9.
Is it possible for you to share the schematic of discharge circuit?
Thanks for your response. Good to know DCC0 bit is for controlling GPIO9.
For the low current, I found out most of the voltage dropped across the mosfet I have not the discharge resistors. That is why the current is so low for me. I am currently testing on lead acid batteries, I assume if I test it with Litthium the problem should be solved due to higher volatge of litthium compare to lead acid battery. I expect the mosfte can become on when tested with Lithium and then most of the voltage dropped across the resistors and as a result the curent goes up.
I have one more question regarding cell balancing. Can I discharge all cells by enabling S pins at the same time? Below is the discharge circuit we are using.
If you are using PWM based then you can balance all at the same time.
Otherwise you should balance alternate cells.