Apple Jailbroken iPhone 4 randomly shuts down when not in use

[nxwing]

I recently got an iPhone 4 from Australia which I jailbreaked and then later on unlocked. Now after I unlocked it, it started to randomly shut down when not in use and the only way to turn it back on is to plug it in to a power source. I tried removing some tweaks and apps from Cydia but it still happens.

Thanks in advance

 

[BORTZ]

I am curious if it still shutsdown when if its not jailbroken. I might be poor contact with the battery or just degradation of the internal components.