hetfield:
The assumption they possibly made was that the cells are sealed, but they
are not. With age, vibration and pressure changes from internal heating &
cooling, they will leak vapour which will accumulate within the enclosure.
Vapour meets electroncis = corrosion and it wouldn't need much deposited
on the pcb to cause measurement error in sensitive analog electronics.
I was going to make some comment about consumer electronics quality in a
billion $ a/c project, but I suppose i'd better not
...
Regards,
Chris