PLEASE HELP! battery problem!

My battery will charge when plugged in to 76% and then stop charging.. I have DONE EVERYTHING i can think of. delete the ACPI compliant control thing. then disconnected my AC adapter and then search for new hardware.. i then opened up the back and took out the battery and held down power for 30 seconds then i started it up and disconnected the AC adapter and Reconnected it... It fixed nothing I NEED help fixing this! i cannot spend $179 for a new battery.. and dell will prolly make me mail it in just to get it fixed... i doubt its the battery i have had this for less then 2 months. and the AC adapter is fine. its not bent. and i have kept it in top condition. am i doing something wrong? i need 100% battery life.. i cannot just have 76% i spent $1099 for this laptop... and im very mad that the battery is having issues.. i DOUBT it dells fault. i think its just windows messing something up.. but please reply ASAP if you have a solution