Why wont my blackberry curve turn on?

-i was at friends house and didnt have a charger so my phone died and was off till 10 this morning. when i came in i put it on the charger and tried 2 turn it on but all it did was give my a battery sign so i left it off 2 charge. 5 hours later i tried to turn it on again and it wont come on i took the bettery out and everything. all it does is every 20 seconds the red light comes on and stays on for 20 sec. then goes off. id there anything i can do witout taking it to the store?try this, make sure the phone is off by pressing red key button, then charge with phone off for an hour, then disconnect charger, remove battery and replace again, it may re-boot again.