You need to find what hack is causing the bad battery life and remove it.
Start installing them one by one and using it for a day to be able to tell what one is the faulty hack. Trial and error.
The JB itself is not the problem, its the stuff people install from cydia that cause such issues.
Try to keep it simple and only install the hacks that you need and use the most.
Dont install everything you see out there.
Sometimes even a good and useful hack will be coded bad and have memory and battery leak. I'd rather remove it than have to deal with terrible battery life or other issues it might cause.