Comment by SideburnsOfDoom

Indeed, that's why I say "keep charge", i.e. be in a steady state such as always leaving at 80% charge. Not charging from zero, and not necessarily charging to 100%.

People who charge electric vehicles at home emphasise that you plug it in as a matter of routine every night (ABC: Always Be Charging) and since it's software-controlled, you can e.g. tell it to charge up to 80%, and figure out the most cost-effective way to do that by 8am.

The ABC of such a ship, is that it would be plugged whenever it is docked, during the turnarounds. And there is enough time in that turnaround to keep charge. It likely also has some downtime at night as well, but that matters less in this case.