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Old Dec 27, 2013 | 03:58 PM
  #45 (permalink)  
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onehundred80
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Joined: Apr 2006
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From: Ontario
Default Re: reverse polarity

Originally Posted by pizzaguy
We have two major ratings in the USA:

1) acc and cca are the same. Both tell us the number of amps the battery can deliver to the starter when cold.
Cold-cranking amps. CCA is a measure of a battery's ability to start a car at 0° F (-18 deg C).
Don't confuse CCA with CA, which stands for cranking amps at 32° (0 deg C) instead of 0°.

Originally Posted by pizzaguy
2) RC (Reserve capacity) The number of minutes the battery can deliver 25 amps at 80 degree C. My battery is rated at 90 minutes.

Your amps rating is the same as RC but stated in a different way. Your rating tells us how many amps the battery can deliver for 60 minutes.
Reserve capacity minutes (RCM), also referred to as reserve capacity (RC), is a battery's ability to sustain a minimum stated electrical load; it is defined as the time (in minutes) that a lead-acid battery at 80 °F (27 °C) will continuously deliver 25 amperes before its voltage drops below 10.5 volts.

Note
80 degrees F. not 80 degrees C. Who's going to be starting a car at that temperature, I've heard of global warning but ........
 

Last edited by onehundred80; Dec 27, 2013 at 04:18 PM.
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