Non-resize battery updates should partially overwrite.
Currently, when there's an update to the battery, the entire battery gets rewritten to the terminal. For non-resize updates, only the relevant parts of the battery should be rewritten.
* Walls should not be overwritten.
* Cells already filled that remain filled should not be overwritten.
* Status should be rewritten if and only if it changes. It wouldn't if the battery was just blinking.
issue