I post this only that it might aid someone else.
I designed this circuit so I could keep track of the peak discharge current for each of my 4 battery banks. It is designed around my unique system. My system has a 60 amp charge controller, 2ea 6000 watt inverters and 4ea 48v FLA battery banks. Each bank has it's own 100a 75mv shunt. That shunt voltage is amplified by separate LM324 op amps. The 5.3 v supply is a adjusted 78L05 regulator running of my existing 48v to 12v supply. It is 5.3v to give enough overhead to obtain 4.5v peak from the LM324s. Clk is from a 555 astable circuit.
I can use the data to evaluate battery bank health and better inform inverter loading.
The first pic is the pcb I used to prove to myself that it works.
Iffn ya see any errors, don't be afraid to say something.
The good news is I am still alive.
Just an update. I recently posted this to the Texas Instruments Forum.
This was their response.
"Hello Barry,
Here are my responses to your questions:
1. Looking over this configuration, it does seem like it will work. My main concern would be with mismatch from the 1kΩ resistors on the input of the INA228. The datasheet says not to use higher than 100Ω, as a higher value can cause measurement error based on the mismatch of the resistors. However, if you need the higher resistors then it can be fine if you are ok with the error.
2. Your equations look correct, but the value you calculated for equation #2 is wrong. When I calculate that equation, I get 1875d (0x753).
You may be interested in the INA4235 or INA4230, which are 4 channel devices. If you used one of these, then you could just read the current register for each shunt and then add them together in the MCU.
Regards,
Mitch
Looks like I am good to go. Gonna hand pick 1% resistors.