I came here to post this bug, so I can confirm. Using latest experimental (5784).
It’s easy to test, just start the game as an industrial cyborg. You start with 260 power storage and battery system already installed.
You used to be able to eat batteries (and car batteries, which is the only thing that actually makes it somewhat useful compared to other power bionics). The option is no longer there, whether the system is on or off, in normal inventory, advanced inventory, or using “E”.