Notebook powers down unexpectedly while battery is still partially full

I have a dv2700t that likes to power down by itself occasionally. By powering down I mean it does not go through the regular windows shutting down sequence, but the screen and all other lights on the keyboard just go off all at once. I tried to power it back up, but it wouldn't turn on unless I plug in the power cord. Today after it powered down for the fourth time, I reinserted the battery, and then wala, it was able to power up by itself. On all of the occasions, the batteries were all partially charged, at least 50% full. So is the battery that is faulty or the actual notebook? I hope it is the battery so that I can call HP to be sent a replacement. I am afraid of sending in my entire notebook because I know it will come back badly scratched. (I have had horrific experience with HP customer service.) Also, let's say I do ask them to send me a battery replacement, will the replacement be brand new? since batteries start to die the moment they leave the factory. Also, my battery is the high capacity kind, how will I know if their replacement is also the high capacity kind? Please answer ALL my questions if possible. Thank you guys so much!

 

Check if the battery pack is loose. Do you have the 6cell or 12cell?

 

Windows has an option to shut down automatically once the battery reaches a certain percentage. Maybe you or someone accidentally changed it to 50%. Check power schemes.

 

I am 100% sure that it's not because the battery is drained that it shuts down, because after I powered it back up again, it says like 78% battery. And I am sure the battery is snugly fitted in its slot. Also, it is stated to be "high capacity 6 cells", so it's probably 8 cells. I just need you guys to tell me whether it is the problem of the battery or the computer itself. Thanks you.

 

The battery could be at fault.

Did you also check what vashts121 suggested?

 

The thing is that I'd tried many times running the notebook on battery for about two and half hours until the battery alert says there is only around 10% of battery left and suggest me to plug in the power cord. So this eliminates the power plan possibility.

 

Windows shuts down properly so that cant be it because you are experiencing direct shut offs.

Inspect your battery connector pins, etc.

If that doesnt work then call up HP for replacement.