I want to measure voltages of multiple cells which are connected in series. I want to do that using a differential amplifier. I read about low input impedance, and what to do about it in this case. So I found this schematic:
I'm wondering, whether it's really important to have high input impedance here, because the battery has a very low resistance, so the input voltage of the OP AMP should be almost the same as the battery voltage, no? So is it indeed better, to add those two voltage followers, or stick with the simpler differential amplifier variation?