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Current measurement is an essential requirement for our BMS, as it will allow us to protect the battery from over-current conditions, calculate SOC, and monitor solar/grid charging. Being able to calculate SOC (state of charge) is quite important, so the more accurate we can measure current, the better we can calculate our power usages. Any direct measurements that tap onto the high voltage bus must be properly isolated from the low voltage system. Any current measurement circuits must be able to measure anywhere from our lowest current draw when our array is charging and our battery is near it's maximum voltage (1kW/150V ~= 6.67A), to our maximum current draw with motors fully on and our battery pack near empty (15kW/(2.5V/module * 36modules ~= 167A). To be conservative, the circuit should be able to provide accurate measurements from ~1-5A to ~200A without significant errors.
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