Comrade said:
c.) What is the max rshunt mOhm setting in your firmware?
It's much more likely to be the minimum mOhm setting that would be relevant, as I expect the wire will have lower resistance than the typical shunt does, for short lengths. These are the relevant sections from the CAv3 online product info page, with the most likely most relevant section (for ebike11) in bold, and the specific value range underlined:
[ Cal->Range ]
Chooser to select the shunt and current range. The Low range mode is appropriate for ebikes while the High range mode is intended for motorcycles and larger EVs. This affects the allowable shunt range and determines if power is displayed as W or kW.
Lo (W): This mode is intended for systems with shunt sense resistors that are in the 1-9mOhm range. Current measurement resolution is 0.01A and power is shown in watts.
Hi (kW): The high range mode is intended for high current systems that have shunts which are in the 0.1-0.9 mOhm range. All power units are shown in kW instead of W and the current measurement resolution is 0.1A. In addition, all current and power feedback calculations are also affected by the chosen range mode, so that an AGain setting of 50 in low range mode would be equivalent to 500 in the high range.
[ Cal->RShunt ]
This setting calibrates CA current measurement. The CA is only as accurate as the calibration value for the current sense shunt resistor. Most controllers with direct plug-in CA connectors have resistances in the 1.5-6 mOhm range and the Stand Alone CA shunts are 1.00 mOhm. Specifications of high current shunts used in larger EV's are not typically rated by shunt resistance but instead indicate the current draw that causes a 50mV drop. For example, a 200A 50mV shunt has a resistance of 50mV/200A = 0.25mOhm.
[ Cal->Zero Amps ]
This setting calibrates the CA zero current measurement and should be adjusted if the resting current shown in the CA screen is something other than 0.0 amps or watts. The live voltages on the Lo and Hi gain current amplifiers are displayed in real time and should be approximately 2.5V. Pressing the right button sets the 'Zero Amps' offset from the present live amperage measurement. After releasing the button the new Lo and Hi voltage offsets are displayed.
[ Cal->VScale ]
This setting calibrates CA voltage measurement. The factory calibration is about 31V/V using the CA internal voltage divider. If an external divider is employed, then VScale must be adjusted to match the voltage scaling ratio.
Here's a page with some info on wire gauge vs resistance per 1000-feet, including temperature values, etc. It also has links for other size standards, other wire types than copper, etc.
http://www.interfacebus.com/AWG-table-of-different-wire-gauge-resistance.html
These are the copper wire tables from that page:
Something to note: It has been shown in various posts around here that not all wires are actually the AWG value they state in their sale ads (some larger, some smaller), especially from places like aliexpress, amazon, ebay, etc. Same for what comes on controllers, motors, etc.
Another issue is that some wires have been shown to not be copper (or not all-copper), in various ways.
So the resistance stated in a chart like the above may not be what is actually seen on a wire, so it might be more accurate to measure the voltage drop across the wire length for a known current and calculate it's resistance (as you do) than to rely on the chart.
It might not make much of a difference to the end-result readings on the Cycle Analyst, but in case readings are significantly different from expectations, it's something to check.