My first Sonicare eventually died of a battery failure 20 years ago. My second would not die and I was stuck buying the old style heads that were hard to clean.

My first Sonicare eventually died of a battery failure 20 years ago. My second would not die and I was stuck buying the old style heads that were hard to clean. I finally gave in and replaced it just recently. Modern lithium cells last forever in low drain, low duty cycle applications like a toothbrush.