Cremating a person with a big lithium battery encased in an airtight metallic casing is also a bit of a hazard. Implantable cardioverter-defibrillators add also a few big capacitors to the mix. There have been quite a few crematoriums destroyed or damaged by pacemaker explosions in the last decades.

Iain Banks' _The Crow Road_ starts like this:

> It was the day my grandmother exploded. I sat in the crematorium, listening to my Uncle Hamish quietly snoring in harmony to Bach’s Mass in B minor, and I reflected that it always seemed to be death that drew me back to Gallanach.

Fantastic book, with possibly the best opening line ever, and yes, she does have a pacemaker.

http://www.tor.com/2009/06/22/a-funny-book-with-a-lot-of-dea...

They planned for that. Those devices were designed to survive cremation without leakage.