On Thu, 13 Sep 2007 05:07:46 -0700,
wrote:

Well, that was very quick! For a suplementry question (no extra
points i'm afraid) has technology moved on since the 70's? or are
todays chargers still a transformer, rectifier and a fuse in a box?

Right back in the '30s they used a variable rheostat and a meter to
control charging current carefully. By the '70s this had been abandoned
in favour of more robust batteries and cruder chargers with no current
control at all.

Not until the '90s did "retail" grade chargers start to see any sort of
electronic intelligence, and even that was simplistic and far from
universal.