Help With Laptop Battery

Sorry if there was a thread on this or a similar subject, but I was unable to locate one even ten pages back through this section.

I own a five-year-old Sony Vaio PCG-V505DC2 notebook, and I recently replaced the battery. The old battery would claim to be 100% charged (or rather my Windows Power Meter claimed as much), but then at around what was claimed by Windows to be about 45% capacity remaining my notebook would turn off. It wasn't going into hibernate mode; it was just shutting off completely, and it would not even so much as light up the LEDs on the case upon sliding the power switch on. This thing was dead. So I purchased a new battery, and after a few charging and recharging cycles (which were all conducted according to the directions) the battery was able to charged to 100% capacity. For the first few times running off of battery power on the new battery my notebook would go all the way down to 0% capactity and proceed to turn off. But then after a few of these complete runs it began to turn off at around 45% again every time I ran it on battery and has been doing so ever since. My hunch is that it is some sort of software issue considering that two different batteries have malfunctioned in exactly the same way, but I am no expert and have found no help on this issue from a variety of other resources. Can anyone help me out on this?

 

instead of giving us the %, please state the battery life in hours:minutes instead.

% is just an on-the-fly calculation

 

Windows can't really accuratly guess the battery's charge. Always take what it says with a grain of salt.

Check at which levels Windows shuts down. My laptop shuts itself down when the battery reaches 8% and gives a warning when it reaches 10%. You can find these settings under power management.

Also make sure your system isn't running at full speed all the time. Maybe there's an app hogging the CPU never allowing it to slow down.

 

Alright, under all types of conditions/settings/# of apps open/etc. the computer is always shutting down at 40%.

 

Follow the advice above this, it might help you it will definitely help us to help you. First how long does it take to shutdown (get to 40%) with normal usage. This might help us to speculate is it the meter or something else. Next go into power management as suggested. It is possible you have it set up to shut down at 40%. I don't think that is the case but until you start ruling things out very hard to help. All any of us know right now is second battery shuts down at 40%. If this is after 3 hours then bad calibration if after 1 hour maybe something else.