On Sat, 05 Jan 2019 11:47:26 -0000, Dave Plowman (News) wrote:

In article ,
Commander Kinsey wrote:
No alternator I've ever seen stays at 14.4v when the battery is
charged. It would very soon fry the battery. And modern batteries are
semi sealed and don't like gassing.

Maybe modern cars have a regulator to stop that,

Pretty well all cars - even in dynamo days - have a regulator. In most
alternators, it's built in.

I've heard the term "regulator" used for cars, but I thought it was to change 3 phase AC into DC, just a big bridge rectifier.

but older cars (and I
mean around the turn of the century ones, not vintage) don't. If you
put a meter on the battery when the engine is running, it's always over
14V. I assume batteries don't really mind that as long as it's just for
driving time - they'd be upset if you did it 24/7.

If you check the battery volts just after a cold start, you'd be right.
You need to hook up your meter to show the volts after some time running,
when the battery is charged.

I wasn't aware lead acids were so fragile. I have my old car connected to an old Bradex 4A charger 24/7, as the alarm runs the battery flat. The charger indicates it's delivering 0.5 amps after it's been sat for a while, and I've measured it at 14.4V. Surely charging a 60Ah battery at 0.5A (which is a 5 day charge!) can't possibly break it?