Well heck, I just re-read my post...sounds kinda grumpy. Sorry about that, didn't mean it that way. I'll tell you that my recovery from the first surgical implant was not that bad...the second one, they had to not only scrape the spine but scrape the scar tissue from the first surgery and they messed up a few nerves in the process. So, don't mess around after the first surgery and you won't have to worry about a second one !
Actually, no one knows why the leads migrated, and they say that they migrate more with cervical vs. lower spine. Your only worry about the battery is, don't let it go down to nothing. That will actually de-activate it, and it often requires surgical replacement of the battery. mine is just under the skin, lower back right side. Takes me about 1-1/2 hours to charge every 3 or 4 days....just strap it on while watching tv and you're good to go. I'm not sure which unit you are getting...with mine, I wear two med tags. You have to watch things, like no mri's and no defib with some of the units.
You have any questions, I'd be happy to try and answer them...I've been living with the implants for 3 years now. My trial didn't have the best of results, but we were at a point where anything in this world was worth a shot.
Bill