Author Topic: Cold Cranking Amps to Amp Hour formula?  (Read 47991 times)

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cyplesma

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Cold Cranking Amps to Amp Hour formula?
« on: July 18, 2005, 05:09:28 PM »
is there a formula to convert cold cranking amps to amp hours?
« Last Edit: July 18, 2005, 05:09:28 PM by (unknown) »

ghurd

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Re: Cold Cranking Amps to Amp Hour formula?
« Reply #1 on: July 18, 2005, 11:24:33 AM »
Like apples to water heaters.

Not very related to each other.


CCA is how much it can supply in a short burst.

AH is the total it can supply until it is dead.


G-

« Last Edit: July 18, 2005, 11:24:33 AM by ghurd »
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pyrocasto

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Re: Cold Cranking Amps to Amp Hour formula?
« Reply #2 on: July 18, 2005, 11:55:51 AM »
Ghurd is right. I think you need to do a search about the diffence between deep cycle batteries and starting batteries...


If it has cold cranking amps it's probably not much good for a power system.

« Last Edit: July 18, 2005, 11:55:51 AM by pyrocasto »

cyplesma

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Re: Cold Cranking Amps to Amp Hour formula?
« Reply #3 on: July 18, 2005, 11:59:29 AM »
I was wondering about the whole deep cycle - starting battery thing. just a case of denial.  deep cycle it is.
« Last Edit: July 18, 2005, 11:59:29 AM by cyplesma »

Nando

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Re: Cold Cranking Amps to Amp Hour formula?
« Reply #4 on: July 19, 2005, 06:08:51 AM »
The definition of the Cold-Cranking Amperage (CCA) of an automotive battery is the amount of current a given battery can deliver for 30 seconds at zero (0) degrees F without dropping below a specified cutoff voltage (manufacturer-specific, but usually 10.5 volts). The value of CCA will change with battery temperature, CCA increasing with higher temperatures. The following de-rates a given battery CCA to ambient temperature. Inputs are CCA in amps, the CCA rating temperature (usually 0 degrees F), and the battery temperature in degrees F.


http://www.bgsoflex.com/ccatemp.html


Has a "calculator" to estimate the CCA of a specific battery you may have


Regards


Nando

« Last Edit: July 19, 2005, 06:08:51 AM by Nando »

Nando

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Re: Cold Cranking Amps to Amp Hour formula?
« Reply #5 on: July 19, 2005, 06:13:09 AM »
ADDING to this message, it takes in consideration the internal resistance of the battery and the storage capacity


Nando

« Last Edit: July 19, 2005, 06:13:09 AM by Nando »

Ungrounded Lightning Rod

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Re: Cold Cranking Amps to Amp Hour formula?
« Reply #6 on: July 19, 2005, 01:23:53 PM »
cold cranking amps are related mainly to plate surface area


amphours are related mainly to amount of material in the plates.


So two batteries with the same amount of plate material, one with a lot of thin plates and the other with a few thick ones, could easily have the same amphour rating and wildly different cold cranking amps.


(There are other differences between a deep cycle, a starting, and a multipurpose battery, too.)

« Last Edit: July 19, 2005, 01:23:53 PM by Ungrounded Lightning Rod »

Bruce S

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Re: Cold Cranking Amps to Amp Hour formula?
« Reply #7 on: July 20, 2005, 07:30:17 AM »
Please make sure and use all the wise information Given all of the above, however.


There was ONCE a Long time ago..... a reference made by the automakers of MG midgets and such.

They used to use 2 of the 6 volt batteries to make sure those cars where weighted correctly, and that they had enough juice to get them to where they wanted to go and have enough juice for lights.

 They where of course 12 volt systems , and back then they thought that having 2 batteries would be a better fit. These were back then, rated according the European standards in Amp hours, and 2 together equaled 12Vdc at 56Ah. They and everyone, except the purists, have since switched to one 12 battery.

According to the old books a 400 - 450 12V battery would be the same as 2 6Vdc 56Ah batteries.

So in a MUST use car batteries due to some unknown reason..... being poor, have 200 laying around,etc...

We could say that a 450 CCA battery is at least close to a 56Ah battery.

I know: this goes against all the rules of using batteries the correct way to get the maximum life and usage and that this is in no way a formula, but.... if MG used it then it might be okay.

No flames please , just trying to be helpful

:-))

« Last Edit: July 20, 2005, 07:30:17 AM by Bruce S »
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ghurd

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Re: Cold Cranking Amps to Amp Hour formula?
« Reply #8 on: July 20, 2005, 08:12:06 AM »
And for the last 6 months I have been starting my old junk car with a 12AH AGM (deep cycle) in a little 'Jump Starter' box.

The little battery seems just fine.


The junk car is too easy on gas to give up right now  :)

G-

« Last Edit: July 20, 2005, 08:12:06 AM by ghurd »
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Dennis the bus dweller

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Re: Cold Cranking Amps to Amp Hour formula?
« Reply #9 on: July 20, 2005, 07:12:17 PM »
Hi Gang

I have 6 / 6 volt / 820 Ah deep cycle batteries that also are rated at 2000 CCA in my school bus / home. There wired for 12 volts. There made by Rolls. There pretty heavy but there great.


Peace along the way

Dennis the bus dweller N.Y.

« Last Edit: July 20, 2005, 07:12:17 PM by Dennis the bus dweller »

pyrocasto

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Re: Cold Cranking Amps to Amp Hour formula?
« Reply #10 on: July 20, 2005, 07:23:40 PM »
Then I'm guessing that's a Dual Cycle battery?
« Last Edit: July 20, 2005, 07:23:40 PM by pyrocasto »

ghurd

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Re: Cold Cranking Amps to Amp Hour formula?
« Reply #11 on: July 21, 2005, 04:15:04 AM »
Some of the newer Trojan deep cycles now have a CCA and AH rating.

It is just confusing the matter, IMHO.  It just about takes 2 books and 6 brochures to tell what the battery is supposed to be.

G-
« Last Edit: July 21, 2005, 04:15:04 AM by ghurd »
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nothing to lose

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Re: Cold Cranking Amps to Amp Hour formula?
« Reply #12 on: July 25, 2005, 06:24:39 PM »
Funny you should mention that :)

I just got home from Canada and such and about 6 vehicles here have dead batteries for some reason. They only sat un-used about 2 months but are totally dead, not just low.

Anyway I used that little Xantrex power booster plus box I have and started them all. A couple I had to jump more than once. I think when I took the battery out the other day it is only a 20amphr, and I think it is a sealed lead acid deepcycle though not sure, it could have been an AGM. I tossed a rod on the aircompressor and the inverter is acting up (probably from running in the rain a few times), but it's still a great booster pack.


Anyway, 20 amp hours does alot of starting of engines!! V6 3.3, Jeep straight 6, V8's, etc..

Always nice to have those jumper boxes handy


At one time I saw a formula for close geussing CCA to amp hours but I forget what it was now since I never use it. I don't think it was right anyway, to many varibles in the way batteries are manufactored for cars. Some are good and last forever, others die an early death, both are rated like 650CCA, both are well cared for. Has to be a difference inside the case that makes them die early and that probably effects the amp hours available also. I would be willing to bet the better built 650CCA battery that lives long would also provide far more amphours than the junk one that dies young, even though they are both rated the same CCA.

« Last Edit: July 25, 2005, 06:24:39 PM by nothing to lose »