Battery Rating vs Capacity Monitoring
Some things: Shipping batteries in the US requires the Watt-Hour rating to be marked on the battery, and the rule is to use the "nominal" voltage. So LFP uses their 12.8v figure for that 100AH x ...
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You would need some test equipment that would adjust the load to the changing battery voltage and hold amps constant.
Shunts will be rated in amps as a maximum before they heat up and change calibration. They are also rated in mV to match the calibration of the meter. Those mV are the calibrated voltage drop.
Example of shunt rating
Shunts will be rated in amps as a maximum before they heat up and change calibration. They are also rated in mV to match the calibration of the meter. Those mV are the calibrated voltage drop.
Example of shunt rating
