@brightwood
Is your post correct you have 8-9 hours left on your battery?

I don't want to alarm you but if that is correct you need to contact your cardiologist immediately. ICDs and Pacemakers are usually changed out when batteries get low way beyond letting them get down to the 8-9 hours left. This is because what you get on battery life is an estimate. Pacemaker can use more or less electrical over time and things like wire resistance can affect them.

Not a medical doctor just passing on what I have learned from my Mayo EP team and 20 years personal experience with having a ICD/Pacemaker.