Hi! Now that a number of MNT Reforms are in the field, it appears that the heuristic that determines “the batteries are now full” should be tweaked a bit. The charger in your case is probably balancing the cells near the upper end and doesn’t decide that it’s really full now. Normally a full charge takes roughly an hour, maybe a bit more if the cells are really drained.
I would recommend to use the laptop on batteries for 2-3h and then charge it again.
I will collect some more feedback and then tweak the LPC firmware to detect full charge more reliably.