Help with custom Morningstar Tristar PWM setup

Something has to cause the voltage surge. I'm fairly certain the surge is from a lot more current going into the battery. Where did this extra current come from? Are there other loads in your setup that disconnect?

You say the inverter shuts down when voltage approaches 14.8V. The video doesn't indicate the exact voltage when it quits. Why not connect a light to the inverter to get a better understanding when it quits. I think the light will go out just when the surge begins.

Sal