Should I replace my battery?

Hi, As there are many variants in the P55W range, how long have you had the laptop? If it is less than 1 year, it is still covered by the manufacturer's warranty. If it is only just over a year old I suggest that you still contact Toshiba and voice you concern regarding the problem saying that you have always maintained it correctly etc. Here is a link to an Ifixit question where some of the symptoms are close to what you are experiencing. You may wish to look at it before you decide on the battery, as replacements are not cheap. Fully charged, won't turn on anymore