I want to measure my DC voltage source (aka batteries), vs my known Dc voltage from my DC-DC regulator. To do this I'll need a voltage divider. I can calculate the resistances I need - but what I'm not sure about is the over all level of resistance I should go for.
If the voltage divider resistance is to low, I'll be burning current for no effect. If it's excessively high.... is there any downside if the current is near zero? Should I just got for 100K ohms and leave it there?
The math is easy. But picking the right target? That's hard.