(Full disclosure: I'm a newbie.)
I'm trying to measure my 4S lipo's cell voltages using an Arduino Mega. I know that I should use a voltage divider (actually, several of them) and I think I understand how it works. I also know about the voltage difference relative to GND would increase by up to 4.2V for each cell, and at 4th cell, it can be over 16V so I should be safely dividing it down to max 5V. However, I'm confused with what resistance values should I use for the divider(s). Wouldn't a low resistance value mean effectively shorting the lipo? Would a too high resistance value cause incorrect readings? In this context, what is a "low" resistance value and what is a "high" resistance value? Or are all resistors already way above that limit and I can use them safely? I've got all types of resistors from 47R to 1M, but I don't know what to use.