HELP! Problem with battery status i9100

hi,
I have a battery problem in my Samsung Galaxy S2 i9100, my battery when it's under 30% discharges very fast.
Also if I reboot my phone when battery is under 45% or less, my mobile doesn't turn on, it shows that battery is over. (but in true still have battery.) Then when i charge it, the mobile shows that battery has 1% charged, but after 5 minutes, shows the real percentatge, the 45% or what was charged. I have tried everything but still I have the same problem.

I have bought a new battery,
and I have calibrated the battery two times (with the app Battery Calibration and also deleting my self the batterystats.bin).
When The problem started I was using cm10.2, but now I have cm10.1, but I have the same problem.

Could you help me please?
thank you


(sorry for my english, I'm not an english native speaker)