I've jailbroke my iPhone for years now, but I've never known
My battery drain as fast as now, to the point where I've booked
Myself in at the apple store cos I thought I had a problem, so
Before I took it to the apple store I'd do a little test and completely
Restore it and not JB it, to see if it was the JB that was the problem!
And, basically JB is the problem, the night before I charged it up and
When I woke up it was 87%, today I did the same thing and it's 97%
So what I'm basically asking is, which JB add Ons use the most power?
So basically I can avoid them..
Cheers in advance?

Hacktivation or restore from iTunes backup are the two most common reasons for battery life problems.

Otherwise, it is possible that it is a hardware issue.