172SP - Voltage variation cold n dark vs active runway start

As a cockpit builder i’ve noticed an issue with the 172 voltage readings. FSUIPC displays the values of what the sim is outputting for various instruments.
When I use FSUIPC to trigger my annunciator LED’s my voltage warning is set to go off at a specific value to mimic what the sim is indicating the voltage annunciator warning is triggered.
The problem is the resting voltage varies when starting cold and dark or starting running on the active runway. For example, after starting on the ramp cold and dark and turning on all available lights, avionics and switches (as a test) the max volts read roughly +3, all electrical systems are drawing 3 more amps from the battery than the alternator can replace.
If i start the sim on the active runway with engines running and turn on all available electrically drawn systems the voltage is reading +6 or more in the same configuration, drawing more power on the battery but at twice the rate as if i started cold and dark on the ramp.

First picture is cold and dark startup with all available electrically drawing avionics and switches on.

Second picture is starting on the runway (engines already running) turning on the same configuration of switches as if i started on the ramp, showing +6 amps being drawn on the battery.

The program being used is mobiflight to read the fsuipc / msfsevents coming from the sim so it’s not the program doing any of these variances, it’s just a vessel to display and trigger external homemade cockpit components. The values are being given to fusipc by the sim and fsuipc is just delivering those values to mobiflight. So the question is, why is the sim drawing more amps in a fast start situation than it is in a cold and dark when put to the same configurations? The steady state values differ by approximately 3 amp variance in each scenario. If i use the fast start and fly around for a few hours i’m constantly drawing 3 more amps on the battery in any configuration state than if i used a cold and dark start.

In the grand scheme of things this isn’t a major bug but I can’t think of any reason why this would be occurring naturally.

What you will find, I believe, is that the Amp gage in the 172 is backwards.
The plus and minus are reversed.
Ther are a few planes in here with that issue.
There is also a thread on it here.

that doesn’t explain the situation i’m stating. whether it is or is not reversed it’s still drawing more (or less) power on a hot start runway sim start up than it is from a cold n dark startup.

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Does the cockpit gage display likewise indicate that load difference?

yes, very slight to tell on a steam gauge but yes it does show a difference. and that’s also evidenced by the fsuipc values which are taking the readings from the sim and displaying them digitally.

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