Battery charging

So let's say I've got a discharged car battery. How long would one
have to drive the car, for the alternator to fully charge it up?

Michael

<mrdarrett@> wrote in message
news:c5bf0137-a047-4d8c-899d-9afef7afd3d6@r15g2000prd..com...
> So let's say I've got a discharged car battery. How long would one
> have to drive the car, for the alternator to fully charge it up?
>
when that happens to me-I drive roughly 10-20 miles on the freeway with no
lights or air..(I have used the air on low and it still charged up)

On Aug 22, 4:23 pm, mrdarr...@ wrote:
> So let's say I've got a discharged car battery.  How long would one
> have to drive the car, for the alternator to fully charge it up?
>
> Michael

a 600 amp battery a 100 amp alternator or a 60a, go figure. What is
dead, 0v, 12v? 13.3 is full charge and you will run the blower lights
etc so use a real charger. So nobody can say.

On Aug 25, 12:41 pm, SMS <scharf.ste...@geemail.com> wrote:
> Daniel wrote:
> > While it is true higher engine speed is required for full output, it
> > is an exaggeration to say it is zero or nil at lower speeds
>
> It's more than an exaggeration, it's simply incorrect. There is very
> little current draw from the alternator when the vehicle is idling,
> unless some heavy current draw accessories are on, such as the
> headlights. The battery will charge, albeit more slowly than if the
> alternator is running at a higher rpm.
>
> Alas, just tried to start the 4Runner this morning, after several weeks
> of only using the Camry, and it had a dead battery. At least Costco
> doesn't hassle about pro-rated refunds.

Generators used to not charge at idle, 600 rpm, alternators are more
efficent, at least my gen never charged at idle.

On Aug 25, 5:03 pm, SMS <scharf.ste...@geemail.com> wrote:
> ransley wrote:
> > Generators used to not charge at idle, 600 rpm, alternators are more
> > efficent, at least my gen never charged at idle.
>
> This may be true, but it's literally been decades since generators were
> used on cars.

mine was a 54 Buick.

Sure generators were more expensive and complex than alternators with
a diode bridge.

But alternators don't charge at 600 RPMs either.

On Aug 25, 11:13 am, ransley <Mark_Rans...m> wrote:
> Generators used to not charge at idle, 600 rpm, alternators are more
> efficent, at least my gen never charged at idle.

On Aug 27, 7:52 am, "Stubby" <William.Plummer*NO*SP...@alum.mit.edu>
wrote:
> "ransley" <Mark_Rans...m> wrote in messagenews:fa490e17-2455-498f-947a-5f8ad1e9622e@y21g2000hsf..com...
>
> On Aug 25, 5:03 pm, SMS <scharf.ste...@geemail.com> wrote:
>
> > ransley wrote:
> > > Generators used to not charge at idle, 600 rpm, alternators are more
> > > efficent, at least my gen never charged at idle.
>
> > This may be true, but it's literally been decades since generators were
> > used on cars.
>
> mine was a 54 Buick.
> ---
> GREAT car!   Mine was a '53 straight-eight stick shift.  It was so smooth and quiet that my mother managed to leave it running when she and her friends went into a bridge game.  A cop tracked her down and dangled the keys in front of her and said, "Forget something?"

Did it have the starter built into the gas pedal, and two heater
cores, one under the seat, mine was a 170 cu 140 hp V8 and dynaflow
trans. The days of no AC or power steering.

Batteries should clock in around 12.5v.

13.5-15.0v are charging voltages from alterntors with sufficient
output. How's your at 2000 rpms?

On Sep 13, 6:25 am, ransley <Mark_Rans...m> wrote:
> 14.4?  dont think so, fully charged is closer to 13.3 and that is what
> my alternators put out. 60-90a alt output, ok, but running just a
> motor is maybe 3-5a. There is alot of extra alternator capacity in
> newer cars, do you remember 30a Generators that did Not charge at
> idle, I do. 14.4v cooks a batery, check its v after stopping and
> before you drive it the next day, stabilised v of 100% is 12.8.

On Sep 13, 8:41 pm, johngd...@m wrote:
> Batteries should clock in around 12.5v.
>
> 13.5-15.0v are charging voltages from alterntors with sufficient
> output. How's your at 2000 rpms?
>
> On Sep 13, 6:25 am, ransley <Mark_Rans...m> wrote:
>
>
>
> > 14.4?  dont think so, fully charged is closer to 13.3 and that is what
> > my alternators put out. 60-90a alt output, ok, but running just a
> > motor is maybe 3-5a. There is alot of extra alternator capacity in
> > newer cars, do you remember 30a Generators that did Not charge at
> > idle, I do. 14.4v cooks a batery, check its v after stopping and
> > before you drive it the next day, stabilised v of 100% is 12.8.- Hide quoted text -
>
> - Show quoted text -

You have read Battery University, 13.3 is what a battery needs to Be
fully charged, 12.8 is a stabilised V of where a fully charged battery
settles at. An Example, I bought a new battery , it showed 12.8, but I
took it home and it tested 80% Charge and took 6 hrs to get to 100% or
13.3, then it settled back to 12.8, It has to be pushed temporarily
to get a peak charge, you cant get that by only charging to 12.8

On Aug 25, 6:03 pm, SMS <scharf.ste...@geemail.com> wrote:
> ransley wrote:
> > Generators used to not charge at idle, 600 rpm, alternators are more
> > efficent, at least my gen never charged at idle.
>
> This may be true, but it's literally been decades since generators were
> used on cars.

You are correct about generators .They absolutely NEVER CHARGED AT
IDLE OR SLOW SPEEDS.

Another fault they had was the propensity for breaking down in the
coldest time of winter, usuaualy a worn out brush on the commutator.
(Probably caused by the demands of the elctrical system , wipers,
heater motor being used almost constantly in the winter.etc.)Or
sometimes a burnt commutator which meant a new generator or rebuilt
unit.

It wasnt a lot of fun trying to free up frozen bolts in almost
inaccessible places.

However this is the MAIN reason Chrysler brought out cars with
alternators ? They would charge at idle.(Chrysler was the first in
production cars with alternators I believe ?)

At this time (I think it was in the early sixties ?)cars were
beginning to be the electrical energy hogs that they are today and
this was another reason for the move to alternators.

Whatever the reason ? it was only a matter of a couple of years before
ALL manufacturers went to alternators.

To check your alternator out put at idle it should read between 13 and
14volts DC, if it does ?it will charge at idle.