Battery Sony Ericsson XPeria Mini Pro

I've a Sony Ericsson XPeria Mini Pro with Android 2.3.3. I noted that the battery ends really fast. I don't have enable GPS service, Mobile data, Bluetooth. Only phone and wifi. In less than two days the battery is drill out. I don't listen music and I don't play any games. I'd like to know if apps are closing correctly but I can't find any app which tell me which apps are runing (without mixing with the running services). My guess is that may be the services (facebook, what's app, etc) are trying to connect and if I'm not connected to wifi there is no internet so they will keep trying and trying... Could it be the cause? Thanks!