BATTERIES BY THE NUMBERSCCA - Cold Cranking Amps: The number of amps a fully charged battery can deliver continuously for 30 seconds at 0 degrees F (-17.8 degrees C) while maintaining a minimum of 1.2 volts per cell (7.2 v total). This is a measure of battery cranking power. Replacement batteries should have a CCA rating that is the same or higher than the original battery. The bigger the engine, the more CCAs it takes to crank it during cold weather. CA - Cranking Amps: The number of amps a battery can deliver continuously for 30 seconds at 32 degrees F (0 degrees C). As a rule, a battery's CA rating will be 10 to 30 percent higher than its CCA rating. It is less meaningful than CCA for cold climate applications, but it looks good on paper. RC - Reserve Capacity: A measure of how long a battery will continue to provide power should the charging system fail. The higher the amp hour rating, the better - but this number is harder to find and may not even be listed on a battery. What's more, many batteries with high CCA ratings achieve a high initial amp output at the expense of staying power. Date Codes - Number/letter codes that indicate when a battery was manufactured. The number indicates the year, and the letter corresponds to the month (A = January, B = February, C = March, etc.). Fresher is better. Group Sizes - Numeric codes that correspond to a battery's height, width, length and post configuration. The most popular size is now Group 75, with Group 24 being second. Replacement battery group size must be compatible with application and OEM group size.