Backvolts, volts1 & volts2

I have a 5500T with a TCW 6ah backup battery. When I download the logs the system records three voltages, backvolts, volts 1 and volts 2.

1. Where is backvolts measuring voltage? Given my configuration this information is not displayed on the EFIS, at what point do I become concerned by its values?

2. Is it correct that volts 1 is measuring the voltage at the main power connector at the EFIS (pin 1)? Therefore the main system voltage of the device delivering power (battery without the alternator or alternator when it is on?)

3. What is volts 2 actually measuring? Is it voltage potential at the backup power pin (14 on the expansion connector) or is it the information from the IBBS battery monitor (pin 13 on the expansion connector)? When the main power is turned off and the EFIS switches to backup power Battery xx.x Volts is displayed on the EFIS in a warning box. That voltage is not the same as Volts 2 by about 0.5 to 1.0 volts, which implies measurement at different locations.

4. The engine data logs also contains values for AMPs_SHUNT and AMPs_HALLEFFECT. I do not use a Hall Effect Sensor. Are the values recorded in the data logs for the Hall_Effect Sensor just data "noise."

Thanks
Scott

1. Where is backvolts measuring voltage? Given my configuration this information is not displayed on the EFIS, at what point do I become concerned by its values?

It it is the voltage of the backup battery, it is displayed on the status bar when the unit is running on the backup battery.

2. Is it correct that volts 1 is measuring the voltage at the main power connector at the EFIS (pin 1)? Therefore the main system voltage of the device delivering power (battery without the alternator or alternator when it is on?)
Yes, voltage at the unit.

3. What is volts 2 actually measuring? Is it voltage potential at the backup power pin (14 on the expansion connector) or is it the information from the IBBS battery monitor (pin 13 on the expansion connector)? When the main power is turned off and the EFIS switches to backup power Battery xx.x Volts is displayed on the EFIS in a warning box. That voltage is not the same as Volts 2 by about 0.5 to 1.0 volts, which implies measurement at different locations.
Volts2 is usually the voltage of pin 14, if you have an ACM-ECB you can select it to display the TCW battery monitor pin.

4. The engine data logs also contains values for AMPs_SHUNT and AMPs_HALLEFFECT. I do not use a Hall Effect Sensor. Are the values recorded in the data logs for the Hall_Effect Sensor just data "noise."
Yes

Thank you!