if the battery runs out on a laptop while it is being used this is an unexpected shutdown event and potentially damaging to HDD.

What is the consensus when battery runs out when laptop is is in hibernate or sleep? Does this have potential to damage hdd or file table etc?

Should be easy to get the hdd out of the laptop (besides some Vaio Laptops
or Netbooks).

If the hdd looks ok outside there shouldnt be a problem.
You could try to connect it with a USB to SATA adapter
(or IDE if its an old laptop) to another PC or laptop and
check the file system.

If the liquid of the battery went deeper into the laptop then you should
go for a cleaning and service. If its only a little bit, clean it yourself.

1. The Windows system will only work (continue hibernate) on your laptop
or on an exact similar hardware.
2. You can access all files + folders with a USB to SATA (or IDE) adapter
as long as they are not protected (encrypted) .

+++

Hi,

When using hybernate any apps & documents that are open are snappedshot & that is then saved to the hard drive & powered down so the heads are parked.
When sleep mode is used it storesit's current state in ram not on the drive. If battery runs out you would lose any open & unsaved documents.

Loki

When your laptop shuts down or looses power, the hard disk will automatically park the heads and everything should be okay for the next boot up. Hibernate will store the information on the drive untill its powered on and sleep will only turn of systems that use a lot of power. Resulting power failure will park the hard drive and unless you have it hibernating, you might loose any unsaved work.