We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Dave Plowman (News)"
saying something like:

Sounds like a right load of ********.

Think there is something in it - but all good quality batteries are
calcium types these days anyway.

The problem then is the need to keep a calcium battery properly up
without substantially shortening the lives of the vehicle lamps. There
would be very little leeway in it and the slightest wander of the
voltage control would be popping bulbs - which is what seems to be
happening. So much for progress.
Of course, every lighting circuit could be individually or collectively
voltage protected, but that would add a significant cost.