battery level notification bad for custom android app

[halive]

I tried to make android app for nrf51822 hrm proj.The app flows like this: scan--connect--discover service-- setnotification for every characteristic. The Hrm char was firstly notified and I got right updated values everytime. However when I did the same setnotification operation for battery level char secondly, I cannot get level data changed notification.
I am sure the setcharacteristicnotificaion() function is ok, since hrm data can be got rightly.But what's wrong when it came to battery level notification ? As a newbie I am not so familiar with the nrf-tool box android app source. I tried to transplant the code for battery notification into my app, but nothing help,maybe I didnot got the right flow order or code structure. How to fix that? What 's special with battery level characteristic? To make it simple, I noly enabled to notification: hrm characteristic and battery characteristic.

[Hung Bui]

@halive: How do you enable notification for battery level characteristic ? Have you managed to get the service and characteristic after you do service discovery ? You need to call gatt.getService(UUID); to get the service after that you can get the characteristic.