I might be misunderstanding, but charge pumps are already a thing: https://en.wikipedia.org/wiki/Charge_pump https://en.wikipedia.org/wiki/Charge_pump Obviousl

I might be misunderstanding, but charge pumps are already a thing: https://en.wikipedia.org/wiki/Charge_pump https://en.wikipedia.org/wiki/Charge_pump Obviously there's stepping up and down happening on both ends up this cable (since it's probably a 19V lithium ion battery in the computer), but at the end of the day you still need to decide on a safe and practical volts*amps number, and then spec the cables and connectors accordingly.