Comment by numpad0

13 hours ago

Battery voltages are dependent on chemistry, or, standard electrode potentials of metals used. It can't be configured like way past fractions of volts. And Li has about the highest potential among metals, which is kind of the point of using Li. Which means straight swapping NMC cells with any substitute will cause overcharging. Maybe there are cell configurations that could work in series packs, but it can't be simple swap-ins.

You can have an interposer charge controller. It isn't complicated. Many/most cells in consumer products already have one.