"It would seem that even police headcam equipment isn't immune to the sort of heat issues which have bedevilled other items of modern technology in recent times."

The key phrase there is "in recent times". Is it just my poor memory, or has spontaneous combustion of batteries and power bricks only become a problem in the past few years? It's not like the devices are using more power than similar devices in the past, and it's not like we haven't been using the same technology in millions of devices for over a decade. So is there really a product or technology problem, or is it all down to defective workmanship and/or materials in an effort to cut cost?