Battery question.

The battery on my Explorer died a couple of weeks ago. It was 6 years old
but showed no signs of illness before it wouldn't crank the engine anymore.

So I got a new battery from Pepboys which is supposed to be 650 cold
cranking amps. Just to be sure I also took the truck over to AutoZone to get
the charge system checked. They said it was fine but the battery showed only
250 cold cranking amps.

Is it like that with new batteries ? will it charge more ?

The battery dial in the dash shows just under half and the engine cranks
just fine.

Should I be worried ?

650 sounds like a pretty small battery, but since you already bought
it, I would not worry about it as long as it cranks ok.

On Wed, 24 Nov 2004 15:58:57 -0600, "zoti"
> wrote:

>The battery on my Explorer died a couple of weeks ago. It was 6 years old
>but showed no signs of illness before it wouldn't crank the engine anymore.
>
>So I got a new battery from Pepboys which is supposed to be 650 cold
>cranking amps. Just to be sure I also took the truck over to AutoZone to get
>the charge system checked. They said it was fine but the battery showed only
>250 cold cranking amps.
>
>Is it like that with new batteries ? will it charge more ?
>
>The battery dial in the dash shows just under half and the engine cranks
>just fine.
>
>Should I be worried ?
>

"zoti" > wrote in message
...
> The battery on my Explorer died a couple of weeks ago. It was 6 years old
> but showed no signs of illness before it wouldn't crank the engine
anymore.
>
> So I got a new battery from Pepboys which is supposed to be 650 cold
> cranking amps. Just to be sure I also took the truck over to AutoZone to
get
> the charge system checked. They said it was fine but the battery showed
only
> 250 cold cranking amps.
>
> Is it like that with new batteries ? will it charge more ?
>
> The battery dial in the dash shows just under half and the engine cranks
> just fine.
>
> Should I be worried ?
This is why you DONT trust your car to idiots like Autozone/Poop-Boys!
How the hell can he tell it's only producing 250 COLD cranking amps? He
might have seen 250 amps being drawn from the battery when you crank the
starter. 250 Amps is a reasonable amount.
Unless this guy put the FULLY CHARGED battery on a carbon loadpile and
pulled power until he dropped the terminal voltage down to 10 volts he cant
tell what the real "COLD Cranking Amperage" is.
OLD high compression V-8's (GM and Ford) would pull 400 Amps easy. Your
Explorer wont pull that much.
Amp/Hr ratings CAN be deceiving. 65AH/Hr means 65 amps for ONE hour. You can
interpolate this any way you like.65Ah/Hr also means 130Amps for
30min,650Amps for 10 minutes (you will blow the top off it).It also means 1
Amp for 65 hours, DOESNT mean it will start the car!!!
The higher the AH/Hr rating the longer it will last with the lights left on,
the longer it will be able to start the car after sitting.
DON'T be terribly concerned with "COLD CRANKING AMPS" unless you have a
diesel, high compression or a rust bucket thats hard to start.
On the voltmeter you want to see 13.8 to 14.2 volts while running at driving
speeds NO more or less.On a lot of cars the meter is not calibrated, get
used to where it stays, if it moves a lot higher or lower trouble is
near....
Hope this helps.
Sign me......
Tired of Poop-Boys and AssholeZone

>
>

Wouldn't worry about! You've got to kidding me!!!! Take that junk battery
back. Get yourself a "real" battery. At least a Diehard. In my Explorer I
run a 900 CCA Diehard SUV and my Toyota has an Optima battery. The Toy gets
more of an electrical workout, with the winch and the lockers and the
entertainment system so thats why the Optima Red top.
But YES I would definately worry about a battery that is supposed to be
650 and putting out less than half that.

Searcher1

"Big Shoe" > wrote in message
...
> 650 sounds like a pretty small battery, but since you already bought
> it, I would not worry about it as long as it cranks ok.
>
> On Wed, 24 Nov 2004 15:58:57 -0600, "zoti"
> > wrote:
>
>>The battery on my Explorer died a couple of weeks ago. It was 6 years old
>>but showed no signs of illness before it wouldn't crank the engine
>>anymore.
>>
>>So I got a new battery from Pepboys which is supposed to be 650 cold
>>cranking amps. Just to be sure I also took the truck over to AutoZone to
>>get
>>the charge system checked. They said it was fine but the battery showed
>>only
>>250 cold cranking amps.
>>
>>Is it like that with new batteries ? will it charge more ?
>>
>>The battery dial in the dash shows just under half and the engine cranks
>>just fine.
>>
>>Should I be worried ?
>>
>

Searcher, You have got to be kidding me!!! You just like to waste your
money, don't you?

Once you exceed the amps required to turn your engine over the excess cold
cranking amps are as useful and extra spare tires! How many spare tires do
you carry, 10 or 12?

The brand new 2005 F-550 with a V-10 gas engine comes with one 78 Amp/HR,
750-CCA battery.
The brand new 2005 Explorer comes from Ford with a 72 Amp/HR, 650-CCA
battery.
650 Cold Cranking Amps is Plenty for all most all automotive applications.

When you misinform people you do more harm then help...


"Searcher" > wrote in message
news:E79pd.6564$ld2.5772@trnddc05...
> Wouldn't worry about! You've got to kidding me!!!! Take that junk battery
> back. Get yourself a "real" battery. At least a Diehard. In my Explorer I
> run a 900 CCA Diehard SUV and my Toyota has an Optima battery. The Toy
gets
> more of an electrical workout, with the winch and the lockers and the
> entertainment system so thats why the Optima Red top.
> But YES I would definately worry about a battery that is supposed to
be
> 650 and putting out less than half that.
>
> Searcher1
>
> "Big Shoe" > wrote in message
> ...
> > 650 sounds like a pretty small battery, but since you already bought
> > it, I would not worry about it as long as it cranks ok.
> >
> > On Wed, 24 Nov 2004 15:58:57 -0600, "zoti"
> > > wrote:
> >
> >>The battery on my Explorer died a couple of weeks ago. It was 6 years
old
> >>but showed no signs of illness before it wouldn't crank the engine
> >>anymore.
> >>
> >>So I got a new battery from Pepboys which is supposed to be 650 cold
> >>cranking amps. Just to be sure I also took the truck over to AutoZone to
> >>get
> >>the charge system checked. They said it was fine but the battery showed
> >>only
> >>250 cold cranking amps.
> >>
> >>Is it like that with new batteries ? will it charge more ?
> >>
> >>The battery dial in the dash shows just under half and the engine cranks
> >>just fine.
> >>
> >>Should I be worried ?
> >>
> >
>
>

A battery's amp-hour rating is a maximum specification, much like the
horsepower rating of an engine. If you have an engine rated at 400
horsepower, that is its maximum rating at a specified RPM. Assuming that
said rating is taken at the rear wheels, if you put the vehicle on a dyno
and run it at that specified RPM, you should read 400 hp. If you operate
the vehicle at a different RPM - say you're driving at 25 mph - you will see
far less than the rated HP.

However, unlike a horsepower rating, which is an instantaneous quantity,
amp-hours represent energy (which is power over time), divided by voltage.
You can't specify a maximum current output for a battery without some
assumptions. The amount of current (in amperes) that is actually drawn from
the battery will depend on the resistance of the load (in ohms) connected
across its terminals. The relationship between voltage (V), current (I)
and resistance (R) is V = I times R, otherwise known as Ohm's Law. Then I =
V/R, so if R=0 (a dead short), I will attempt to go to infinity. Of course,
a real battery can't produce an infinite current! Obviously, you could
short the terminals together with a conductor, but if you did this, the
current draw would create so much heat that the battery would be destroyed,
if the conductor doesn't melt first.

As Rastis Fafoofnik states in his post below, you have to test the battery
using a carbon pile (which is nothing more than a high-wattage resistive
element), so that the battery will be adequately loaded, but the amount of
current flow will not damage it. During the test, the voltage has to stay
within an acceptable range (if it's +/- 10%, then the range is 10.8 to 13.2
volts), and ideally you will read a current that will stay constant for a
certain period of time, say 250 amps for 2.5 hours, until the battery is
exhausted. If you multiply 250 and 2.5, you get 625 amp-hour. 125 amps for
5 hours gives you the same rating. Of course, in the real world, the
voltage and current will gradually diminish as the battery loses charge, but
you get the idea. The battery has to be adequately loaded for the test to
be meaningful; a battery in poor condition with little or no load might
still read 12 volts across its terminals, but as soon as any substantial
load is connected across it, the voltage drops way down, below the minimum
acceptable voltage.

I'm an electrical engineer and I've specified lots of batteries for power
substations. It's basically an addition and multiplication problem.
Substations have batteries so that supervisory and protective devices can be
operated in case of an outage (if everything runs on AC, and your station
goes down, you have no power and are SOL). You first decide how long you
want the power to last (typically 8 hours), then you add up the load you
need to connect to the batteries. Finally, you multiply that load by the
time you want everything to run, and voila - there's your battery
specification. I'd add 10 or 15% to that to allow for the tendency of that
amp-hour rating to diminish with time (like 10 or 20 years), but you get the
method.

HTH



"RikiTikiTavi" > wrote in message
...
> "Searcher" >
> wrotenews:E79pd.6564$ld2.5772@trnddc05:
>
>> Wouldn't worry about! You've got to kidding me!!!! Take that junk
>> battery back. Get yourself a "real" battery. At least a Diehard. In my
>> Explorer I run a 900 CCA Diehard SUV and my Toyota has an Optima
>> battery. The Toy gets more of an electrical workout, with the winch and
>> the lockers and the entertainment system so thats why the Optima Red
>> top.
>> But YES I would definately worry about a battery that is supposed to
>> be
>> 650 and putting out less than half that.
>>
>> Searcher1
>>
>
>
> Consumer Reports had a car battery issue recently. You might want to
> check
> with them, because diferent makers make diferent sizes and the best for
> Chevs might not be the best for Fords.
>
> One thing, they almost all lie on their specs.
>>
>>
>
> -- Riki
> --Those who live by the sword get shot by those who don't.
>

http://www.uuhome.de/william.darden/

Kevin DeAngelis wrote:

> However, unlike a horsepower rating, which is an instantaneous quantity,
> amp-hours represent energy (which is power over time), divided by voltage.


Bzzzzt! Wrong answer...

Horsepower is a unit of work over time.
Torque is the instantaneous measurement.

<http://vettenet.org/torquehp.html>

But thanks for playing!

-Fred W

Sorry Fred, but I'm afraid that you are wrong on this one. Horsepower is
*not* a unit of energy, but horsepower-hours are.

You may be more familiar with the watt as a unit of power, and a
kilowatt-hour as a unit of energy. One horsepower is equal to 746 watts.
One horsepower-hour is equal to 1 kilowatt-hour. Electric utilities will
bill you for energy used in kilowatt-hours. They don't bill for kilowatts.

Torque is a unit of force over distance, for example newton-meters or
foot-pounds.

These concepts are easily confused. In addition to working as an engineer
for an electric utility, I occasionally teach electric circuits and statics
classes at the local community college. I find that students confuse power,
energy and torque frequently.


"Fred W" > wrote in message
...
> Kevin DeAngelis wrote:
>
>> However, unlike a horsepower rating, which is an instantaneous quantity,
>> amp-hours represent energy (which is power over time), divided by
>> voltage.
>
>
> Bzzzzt! Wrong answer...
>
> Horsepower is a unit of work over time.
> Torque is the instantaneous measurement.
>
> <http://vettenet.org/torquehp.html>
>
> But thanks for playing!
>
> -Fred W

Whoops - meant to say that 1 horsepower-hour equals ).746 kwh. Sorry.

"Kevin DeAngelis" > wrote in message
news:Rvqpd.9213$ld2.6911@trnddc05...
> Sorry Fred, but I'm afraid that you are wrong on this one. Horsepower is
> *not* a unit of energy, but horsepower-hours are.
>
> You may be more familiar with the watt as a unit of power, and a
> kilowatt-hour as a unit of energy. One horsepower is equal to 746 watts.
> One horsepower-hour is equal to 1 kilowatt-hour. Electric utilities will
> bill you for energy used in kilowatt-hours. They don't bill for
> kilowatts.
>
> Torque is a unit of force over distance, for example newton-meters or
> foot-pounds.
>
> These concepts are easily confused. In addition to working as an engineer
> for an electric utility, I occasionally teach electric circuits and
> statics classes at the local community college. I find that students
> confuse power, energy and torque frequently.
>
>
> "Fred W" > wrote in message
> ...
>> Kevin DeAngelis wrote:
>>
>>> However, unlike a horsepower rating, which is an instantaneous quantity,
>>> amp-hours represent energy (which is power over time), divided by
>>> voltage.
>>
>>
>> Bzzzzt! Wrong answer...
>>
>> Horsepower is a unit of work over time.
>> Torque is the instantaneous measurement.
>>
>> <http://vettenet.org/torquehp.html>
>>
>> But thanks for playing!
>>
>> -Fred W
>
>