Can't read the sim and the battery never charge to full.

The iPhone can't read the sim card that i inserted (it say no sim). i try to restart it but sometime it say that i need to activate with the itunes, sometime it can't recognsed the IMEI no. when i try to charge the battery it never show a full bar and somtime it stay on the red no matter how long i charge it. which part is actualy broken? and can it be fix? mine is official unlock iPhone (factory unlock) buy it in russia.