Unattended, unintended system shutdown - why?

[Dan Purgert]

On Sat, 07 Mar 2015 13:14:35 +0000, David Fletcher wrote:

> 
> Then, today, I walked into town for couple of hours, came back, switched
> on my laptop to check my mail and... nothing. Failed to connect. WTF?
> ssh - nothing. ping - nothing. went upstairs to check and it was powered
> off. Pressed the button and it powered up, and is working again. Why? I
> have absolutely no idea. Yes it's running on a UPS so this should never,
> ever happen.
> 
> Any idea why it did this, please?
> 

Could be that the battery's not as reliable as you thought -- how old is 
it? 

In addition to that - have you changed your system layout since getting 
the battery?  E.g. newer / more power hungry server, or other devices 
getting plugged into the battery?