I'm after a little feedback here on peoples perceptions of how long a laptop battery should last in terms of it's length of life.  I brought an HP DV6603AX (my 1st laptop) back in Feb of this year and it's been well used ever since.

I've noticed that the battery gets extremely hot so tend to use a cooling device nearly all of the time now, however the battery is not of the type recently recalled due to overheating problems.

My problem is, the battery used to last about 1 hour (which doesn't seem like a long time to me anyway) before I needed to plug it into mains.  Nine months later, that time has reduced to about 30 minutes (quite a sharp reduction in the last few months actually) making me suspect the high temperatures I experienced before buying a cooling device have had an impact in the battery cells.

What would happen with the battery, up to a few months ago, is it would get to a low charge, warn me then hibernate if I took no action.  What seems to happen now is it loses it's charge really fast, if I'm lucky a warning will be thrown up, but then it just shuts off - something the OS doesn't like at all and I have to tell it to "restart normally".

So, is my battery underperforming, or is it just time to purchase a new one?

Thanks in advance
Steve