On 23/6/19 7:55 am, Commander Kinsey wrote:
On Sat, 22 Jun 2019 18:02:30 +0100, Rod Speed
wrote:

snip

Wrong when there is normally more than the one
wire at the the positive terminal of the battery.

Even if there is an additional wire, explain to us how you
monitor the current in the charging cable with that wire.

With more than one wire, you can see
what the load from the lights etc is.

And you dont even have to do it that way
with modern computer controlled lights now.

I doubt it knows about everything, like how much power you're using from
the cigarette lighter socket etc.Â* Easier to just measure the total load
in one go, than trying to add up precise currents it thinks the wipers
might be using etc.

It isn't concerned about *individual* loads. It looks at the *system
voltage* and operates from that.

And Rod is talking computers,

Because thats what his car has.

But the essence of his question is how cars switch to
trickle charge and AFAIK, the answer is they don't.

The current to the battery does in fact drop
dramatically once the battery is fully charged.

The chemistry of the battery sees to that itself, but it's better for
the battery to lower the voltage from 14.4 to 13.8 when it's full.Â* It's
not as easy as a lithium cell where you just give it 4.2V.


--

Xeno


Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)