Does anyone know if a battery with 675 CCA is the same as a battery with 72 amp hours? Thanks for the help.

 

I believe that is one and the same battery for the Ford. In reality the two numbers do not have to be related at all.

CCA is the number of "cold cranking amps" which is the number of amps a new, fully charged battery can deliver at 0° Farenheit for 30 seconds, while maintaining a voltage of at least 7.2 volts, for a 12 volt battery. The higher the CCA rating, the greater the starting power of the battery. CCA tells you something about plate size, and the connections between the plates, ie - how much juice the battery can instantaneously flow.

Amp hours is the total capacity of the battery and relates to items such as the number of plates. A 72 amp hour battery can deliver 1 amp for 72 hours, or 10 amps for 7.2 hours before the voltage falls to unusable levels. Note that 675 amps drawn for 30 seconds (as in the test for CCA) is equal to 5.625 amp hours draw.

 

PHEW.............you the man!!!! Thanks for the responce. The reason for my question was because I got the class III package on my screw which said that it came with a 72 Amp hour.I just wanted to make sure it was bigger than the standard. Now I need to find out what the standard one is. Thanks again.

 

It used to be 65 amp hours... but I think they are all the same across the board now.

 

Someone told me once that the battery industry rates the amp/hour rating on batteries on a 5 hour test. A 72 amp/hour battery would actually be rated on its ability to deliver 14.4 amps for 5 hours without the voltage dropping below some voltage value (10 V?). They then reflect that 5 hour number back to a 1 hour rating for simplicity.

He said you shouldn't expect a 72 amp/hour battery to deliver the full 72 amps for an hour. He also mentioned that even the 5 hour test was very hard on the battery and that after a heavy discharge like that, the battery could never be charged back up to it's original charge. A very fast or heavy discharge leaves unwanted chemicals on the battery plates that can not be driven off simply by recharging the battery.

I'm not completly certain about the 5 hour rating, but the guy who told me was pretty reliable. Does anyone know for sure if this is true? I have been kind of curious for years now.

 

A 72 amp hour battery would be able to deliver 1 amp for 72 hours not 72 amps for 1 hour. They may do the test in 5 hours but that does not change the definition of amp hour.