weird mbp problems

so basically ive had my mbp for a year now. it keeps shutting off when the theres power left in the battery. it happend like 8 times. when i say power left i dont mean 15 or 10% i mean like 60 and 80%. also when i put the battery in instead of percent charged sign, theres a x in the battery symbol. i took the battery out and the green light has stayed on for 2 days. any ideas?

Seems to me like you got a hardware problem there. When this happened to my iBook, I called applecare and they replaced the machine...