I have a 30 feet line with DC supply 12 V. A motor on the end draws about 0.5 Amps initially (100 ms). It's logic shuts down because of the line's voltage drop caused by inrush current. A capacitor of 1000 uF prevents the shutdown.
However, if I calculate the size of the capacitor that prevents a drop of more than 1 V, a much larger (x50) value comes out (0.5 A * 0.1 s / 1 V = 0.05 Farad).
I figure this is because the supply isn't disconnected but continues to supply power, so the capacitor does not have to provide the current alone.
How can I improve my model so the calculation is closer to the real thing?