I knew my Medtronic Activa-PC DBS generator battery would need to be replaced some day. The average lifespan is 3 to 5 years. Mine was six years old in October 2018.
At the beginning of 2016, my battery level was 2.97v. At the beginning of 2017, my battery level was at 2.91v. At the beginning of 2018 it was 2.85v. It was averaging a drop of .06v a year, so I figured I'd have several more years until it reached the ERI (Elective Replacement Indicated) warning you get when it drops to 2.59v, I was wrong.
I had been in the habit of checking my battery level using my patient programmer about every three months. April was 2.83v and July was 2.81v, right on target. So you can imagine my surprise when I checked it at the end of October 2018 and saw that it was down to 2.76v.
I started checking it monthly, then weekly and now daily and I wasn't liking what I was seeing. The amount of time between voltage drops was decreasing.
As of today, January 21, 2019, it's now at 2.69v. That's a drop of .07v in less than three months. If the voltage drop continues to accelerate, I will get the ERI warning in a few months!!!
My neurosurgeon, Dr. Norton is in the same office as Dr. Bradley, my Movement Disorder Specialist and I have an appointment with her in mid-March. I have already contacted Norton's assistant because I didn't want to wait until March and then find out that he's going to be on vacation or something else that would make him unavailable. Norton's assistant said they could get me on his surgery schedule within two weeks, but I should call if I get the ERI warning before my March appointment.
Looks like this Happy Parkie will soon be getting a brand new generator.
The generator won't stop working when the ERI warning appears. There's a built in cushion of time, it doesn't stop working until it gets to 2.20v. You don't want it to suddenly stop working so remember to check yours regularly.