During a HOLD the holding battery gives what keeps the quarter at the peak
aim. N=1: the peak floor is refiled at P_MAINTENANCE, as for a drain
(SAFETY-83). N>=2: the hold's pin is raised to the floor minus what the
other live batteries may place, so they give first. A site stop still
decides alone. The hold ends on its clock even if the level dipped.
Below the aim nothing changes (rows identical).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
