Well.. First I want to share about my experience to use a Samsung Galaxy Note 2.
At first, the battery was OK with all applications and games before I installed the BBM for Android. Usually I will just charge 1- 2x a day depends on the usage for the apps and games.
After the BBM for Android launched, I installed it and my battery was drained 200% faster than usual. Plus when I charge it, it will just drain and drain.
I thought that the problem is about the battery or the phone charger. After I looked for the condition, the cause is from the application "BBM for Android"
Therefore, I want to give you tips to save your battery that I already tried and it works till now...you can follow my instructions if you want, no force... ;)
1. Hide the updates from all your contacts. (The updates from your friends will absorb a lot of battery because it will keep updating and of course, it will absorb your kuota for internet plan)
click the icon that has 3 stripes > go into the updates > tap longer for your friends name that appears there > click hide updates (to get the updates for your friends again, you can go to the "block contacts"> choose the updates > click the unhide updates)
2. Turn off ALL notifications automatically. (If you want to check your phone, then just go manually to the BBM application to see any notification) or you can choose just some notifications.
3. You can set the brightness to the lowest level.
Actually maybe you can go get the application about saving the battery, but I don't know if it will work... That's all about my tips. If you want to try, I hope your battery won't be drained so fast.