On 02-05-2020 19:10, The Natural Philosopher wrote:
On 02/05/2020 19:05, The Natural Philosopher wrote:
On 02/05/2020 17:31, 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.

The alternator will deliver whatever voltage it meeds to but of course
there would not need to be a particularly large voltageÂ* to charge a
battery that is capable of delivering over 700 A to starter motors
without crapping out

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


Total crap. There is no pint in having a 150A capable alternator to do
THAT

"Not long ago, an 80 amp alternator was considered a high output unit.
Most late model alternators produce 120 to 155 amps or more. Current
output increases with engine speed, from around 20 to 50 amps at idle up
to the unit's maximum output at 2,500 RPM or higher (refer to a service
manual for the exact charging output specifications for your vehicle)."

https://www.aa1car.com/library/charging_checks.htm



It's all in your tin foil head .