Honda Car Forum

An alternator does not need a battery to run.....only to get it
started....after the alternator is running, the battery is of no use...Mind
you on newer cars the computer does come into play, but AFAIK, in theory you
could pull a battery while the car is running and see no side effects...( I
dont reccomend this though, especially with today's cars)
The alternator usually is outputting a little more than the battery voltage
to maintain a trickle charge on the battery, hence why when you get a boost
you are supposed to let it run for a bit.....
As for the original posters question.....the new battery would have nothing
to do with your AC unless whoever put the battery in knocked something AC
related under your hood while putting it in the compartment
TH
"Kevin McMurtrie" <mcmurtri@dslextreme.com> wrote in message
news:mcmurtri-3FF0ED.10501401092003@corp-radius.supernews.com...
> In article <9722d64.0308291348.7d8707c1@posting.google.com> ,
> ozvena@hotmail.com (Peter) wrote:
>
> > I just had my car (99 Accord LX) battery replaced after being
> > diagnosed as "one battery cell failure".
> >
> > After the battery replacement, the A/C seems to be noticeably cooler!
> > Any idea why?
>
> Not much will work correctly when the battery is bad because the
> alternator can't produce a stable voltage without it. A bad or missing
> battery can even damage electronics.

In article <1DV4b.880207$ro6.17831867@news2.calgary.shaw.ca >,
"Todd Howard" <dyolf_knip60@hotmail.com> wrote:

> An alternator does not need a battery to run.....only to get it
> started....after the alternator is running, the battery is of no use...Mind
> you on newer cars the computer does come into play, but AFAIK, in theory you
> could pull a battery while the car is running and see no side effects...( I
> dont reccomend this though, especially with today's cars)
> The alternator usually is outputting a little more than the battery voltage
> to maintain a trickle charge on the battery, hence why when you get a boost
> you are supposed to let it run for a bit.....
> As for the original posters question.....the new battery would have nothing
> to do with your AC unless whoever put the battery in knocked something AC
> related under your hood while putting it in the compartment
> TH
> "Kevin McMurtrie" <mcmurtri@dslextreme.com> wrote in message
> news:mcmurtri-3FF0ED.10501401092003@corp-radius.supernews.com...
> > In article <9722d64.0308291348.7d8707c1@posting.google.com> ,
> > ozvena@hotmail.com (Peter) wrote:
> >
> > > I just had my car (99 Accord LX) battery replaced after being
> > > diagnosed as "one battery cell failure".
> > >
> > > After the battery replacement, the A/C seems to be noticeably cooler!
> > > Any idea why?
> >
> > Not much will work correctly when the battery is bad because the
> > alternator can't produce a stable voltage without it. A bad or missing
> > battery can even damage electronics.
>
>

The battery is absolutely required. The alternator's field magnet is
slow to change and it is the only method of regulation. It can't react
to load changes in a car fast enough to avoid wild voltage swings
without a battery. Most cars won't run at all without a battery.
They'll sputter and stumble until the electronics are fried.

Wild voltage swings? From what? The alternator and the battery are the ONLY
things OUTputting electricity...Alternator outputs AC and the battery
DC....And I agree that most cars wont run without a battery, but I am
positive that is only due to the computer loacated in the car....back in the
day before all of the electronics were added you could run a car with out
the battery.....as a matter of fact you could also run it without the
alternator if it happened to die while the car was running....but I digress
as cars depend heavily on electricity nowadays...
The Alternator maintains a trickle charge on the battery by converting to DC
with a rectifier ( a bunch of diodes), that is why you arent buying a new
battery every 3 months....the alternator also runs all of the electronics
while the car is running, if the voltage needed is more than the alternator
can provide, then yes the battery will also be used, but in todays cars they
are efficient enough that need doesnt arise.
Anyway we have gotten away from the OP's question.....which was how could a
new battery affect AC? It cant, unless Honda is building a different AC
unit, that runs completly off of the battery as most run off of the engine
with a serpentine belt, and the alternator.
Anyway Kevin I hate getting into pissing contests on usenet and to be honest
I am a new Honda owner, coming over from a lifetime of North American cars,
so if you have a link or something that says different then by all means
fire away as I am always willing to learn new things..
Todd
"Kevin McMurtrie" <mcmurtri@dslextreme.com> wrote in message
news:mcmurtri-A649EA.01564302092003@corp-radius.supernews.com...
> In article <1DV4b.880207$ro6.17831867@news2.calgary.shaw.ca >,
> "Todd Howard" <dyolf_knip60@hotmail.com> wrote:
>
> > An alternator does not need a battery to run.....only to get it
> > started....after the alternator is running, the battery is of no
use...Mind
> > you on newer cars the computer does come into play, but AFAIK, in theory
you
> > could pull a battery while the car is running and see no side
effects...( I
> > dont reccomend this though, especially with today's cars)
> > The alternator usually is outputting a little more than the battery
voltage
> > to maintain a trickle charge on the battery, hence why when you get a
boost
> > you are supposed to let it run for a bit.....
> > As for the original posters question.....the new battery would have
nothing
> > to do with your AC unless whoever put the battery in knocked something
AC
> > related under your hood while putting it in the compartment
> > TH
> > "Kevin McMurtrie" <mcmurtri@dslextreme.com> wrote in message
> > news:mcmurtri-3FF0ED.10501401092003@corp-radius.supernews.com...
> > > In article <9722d64.0308291348.7d8707c1@posting.google.com> ,
> > > ozvena@hotmail.com (Peter) wrote:
> > >
> > > > I just had my car (99 Accord LX) battery replaced after being
> > > > diagnosed as "one battery cell failure".
> > > >
> > > > After the battery replacement, the A/C seems to be noticeably
cooler!
> > > > Any idea why?
> > >
> > > Not much will work correctly when the battery is bad because the
> > > alternator can't produce a stable voltage without it. A bad or
missing
> > > battery can even damage electronics.
> >
> >
>
> The battery is absolutely required. The alternator's field magnet is
> slow to change and it is the only method of regulation. It can't react
> to load changes in a car fast enough to avoid wild voltage swings
> without a battery. Most cars won't run at all without a battery.
> They'll sputter and stumble until the electronics are fried.

On Tue, 02 Sep 2003 23:00:15 GMT, "Todd Howard" <dyolf_knip60@hotmail.com>
wrote:

>Wild voltage swings? From what? The alternator and the battery are the ONLY
>things OUTputting electricity...Alternator outputs AC and the battery
>DC....And I agree that most cars wont run without a battery, but I am
>positive that is only due to the computer loacated in the car....back in the
>day before all of the electronics were added you could run a car with out
>the battery.....as a matter of fact you could also run it without the
>alternator if it happened to die while the car was running....but I digress
>as cars depend heavily on electricity nowadays...

Back in the days of DC generators it may have been safe. With alternators,
it is generally recommended that you *never* disconnect the battery. I've
seen this as far back as a 1978 VW shop manual.

>The Alternator maintains a trickle charge on the battery by converting to DC
>with a rectifier ( a bunch of diodes), that is why you arent buying a new
>battery every 3 months....the alternator also runs all of the electronics
>while the car is running, if the voltage needed is more than the alternator
>can provide, then yes the battery will also be used, but in todays cars they
>are efficient enough that need doesnt arise.

Nope - it's the current which counts. The battery also acts as a large
smoothing condenser.

<<snip>>
>>
>> The battery is absolutely required. The alternator's field magnet is
>> slow to change and it is the only method of regulation. It can't react
>> to load changes in a car fast enough to avoid wild voltage swings
>> without a battery. Most cars won't run at all without a battery.
>> They'll sputter and stumble until the electronics are fried.
>
>

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

In article <3i95b.78802$la.1980455@news1.calgary.shaw.ca>,
"Todd Howard" <dyolf_knip60@hotmail.com> wrote:

> Wild voltage swings? From what? The alternator and the battery are the ONLY
> things OUTputting electricity...Alternator outputs AC and the battery
> DC....And I agree that most cars wont run without a battery, but I am
> positive that is only due to the computer loacated in the car....back in the
> day before all of the electronics were added you could run a car with out
> the battery.....as a matter of fact you could also run it without the
> alternator if it happened to die while the car was running....but I digress
> as cars depend heavily on electricity nowadays...
> The Alternator maintains a trickle charge on the battery by converting to DC
> with a rectifier ( a bunch of diodes), that is why you arent buying a new
> battery every 3 months....the alternator also runs all of the electronics
> while the car is running, if the voltage needed is more than the alternator
> can provide, then yes the battery will also be used, but in todays cars they
> are efficient enough that need doesnt arise.
> Anyway we have gotten away from the OP's question.....which was how could a
> new battery affect AC? It cant, unless Honda is building a different AC
> unit, that runs completly off of the battery as most run off of the engine
> with a serpentine belt, and the alternator.
> Anyway Kevin I hate getting into pissing contests on usenet and to be honest
> I am a new Honda owner, coming over from a lifetime of North American cars,
> so if you have a link or something that says different then by all means
> fire away as I am always willing to learn new things..
> Todd

The alternator has a rather high impedance. When the load increases,
the voltage drops until the field coil gains strength to compensate.
When the load decreases, the voltage shoots up until the field coil
fades to compensate.

I had a battery become a mostly open circuit on pre-computer car. Its
internal resistance was something useless like 1 Ohm (1 volt drop for
every amp drawn). Every time I pressed on the brake pedal, the power
flickered so badly that the engine would crap out. The turn signals
just sputtered so I gave up on that. A bunch of capacitors in an audio
amp and the 1 Ohm left in the car battery was all that was keeping the
engine going at all, and it wasn't enough power filtering to have a
single light bulb on. Getting to a auto parts store after push-starting
it was tricky.


> "Kevin McMurtrie" <mcmurtri@dslextreme.com> wrote in message
> news:mcmurtri-A649EA.01564302092003@corp-radius.supernews.com...
> > In article <1DV4b.880207$ro6.17831867@news2.calgary.shaw.ca >,
> > "Todd Howard" <dyolf_knip60@hotmail.com> wrote:
> >
> > > An alternator does not need a battery to run.....only to get it
> > > started....after the alternator is running, the battery is of no
> use...Mind
> > > you on newer cars the computer does come into play, but AFAIK, in theory
> you
> > > could pull a battery while the car is running and see no side
> effects...( I
> > > dont reccomend this though, especially with today's cars)
> > > The alternator usually is outputting a little more than the battery
> voltage
> > > to maintain a trickle charge on the battery, hence why when you get a
> boost
> > > you are supposed to let it run for a bit.....
> > > As for the original posters question.....the new battery would have
> nothing
> > > to do with your AC unless whoever put the battery in knocked something
> AC
> > > related under your hood while putting it in the compartment
> > > TH
> > > "Kevin McMurtrie" <mcmurtri@dslextreme.com> wrote in message
> > > news:mcmurtri-3FF0ED.10501401092003@corp-radius.supernews.com...
> > > > In article <9722d64.0308291348.7d8707c1@posting.google.com> ,
> > > > ozvena@hotmail.com (Peter) wrote:
> > > >
> > > > > I just had my car (99 Accord LX) battery replaced after being
> > > > > diagnosed as "one battery cell failure".
> > > > >
> > > > > After the battery replacement, the A/C seems to be noticeably
> cooler!
> > > > > Any idea why?
> > > >
> > > > Not much will work correctly when the battery is bad because the
> > > > alternator can't produce a stable voltage without it. A bad or
> missing
> > > > battery can even damage electronics.
> > >
> > >
> >
> > The battery is absolutely required. The alternator's field magnet is
> > slow to change and it is the only method of regulation. It can't react
> > to load changes in a car fast enough to avoid wild voltage swings
> > without a battery. Most cars won't run at all without a battery.
> > They'll sputter and stumble until the electronics are fried.
>
>