Mexico? Canada? The Philippines?
Nope... None of the above. There just LI batteries. They are sealed inside a titanium shell and are not replaceable. But of course they are... And they are implanted just under the skin. And, I insisted when they replaced them the last time, that since “I” paid for them, I wanted to old ones. After a bit of fighting I got them. They plug in just like any modern device with a plug. If worst comes to worst, I can replace the batteries and I can do the surgery to replace them. I am an Engineer after all.