Software control of charging voltages?

Based upon this, very useful, article, I'm interested in knowing how to charge to a lower peak voltage. Apparently you can double the lifespan of your battery by lowering the maximum peak voltage by 0.1V, which is a thing I'm interested in! (as opposed to most people, who want more capacity, I'm prepared to sacrifice some capacity for longer lifespan!)

It feels like there should be 3 ways of solving the problem:

• Pull the cord out at 80%?


• Create some sort of hardware between the phone and charger that does something?


• Tell the software to stop charging at a lower voltage?

#1 is clunky and not going to happen. #2 is hard because I'm not a hardware guy, but if anyone has any knowledge in this area I'd be interested in hearing! #3 is best for me, because at least I understand the internals of the phone, but I can't figure out what part of the phone might be in charge (heh...) of this.


So I guess my questions are:
What chip/etc is in charge of handling charging?
Is it possible to hack at this part?
Has anyone done it before?


Thanks!