In article ,
Dave Plowman (News) wrote:
In article ,
Harry Bloomfield wrote:
Dave Plowman (News) formulated on Saturday :
So you are guessing it charges a low battery at 140 amps? ;-)

No, there would need to be a rather large difference in voltage between
the alternator and battery, to achieve that and as the battery attains
a charge, its voltage rises quite rapidly.

I would suggest nearer an initial 20amps, which would rapidly fall to
maybe 3 to 6 amps. A flat to full charge time when being driven, can
require 6 to 10 hours of being driven.

6 to 10 hours driving is far more than many cars ever get.

Which is why it is always best to put such a battery on a mains charger
for 24 hours, if at all possible.

Given most cars these days have plenty alternator capacity, there really
shouldn't be the need to ever charge the battery externally. Unless the
car is not used for such a time as the battery goes flat.

It's now 7 weeks since I used my car.

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle