What’s the Difference Between CCA and CA?

We're talking about cranking batteries today, or otherwise known as engine starting batteries. 
Cranking or engine starting batteries are rated in cold cranking amp or cranking amp. Cold cranking amp is abbreviated CCA and cranking amp being abbreviated CA. The difference in these two ratings are cold cranking amp is measured at -17.8 degrees Celsius and cranking amp is measured at 0 degrees Celsius. 
In a cold weather engine starting application such as our everyday automobiles and trucks that battery's typically going to need to be measured in cold cranking amp because it might not be unusual to go out and start that vehicle in -18-degree weather. On the other hand, batteries rated in cranking amps are typically known as marine starting batteries and are rated at 0 degrees and typically we're starting those engines when the temperature is above zero and they don't require as much power. So, the cold cranking amp rating is always going to be a lower number than the cranking amp rating and many batteries have both ratings on it for comparative purposes. 
Cranking amp batteries have more plates and thinner plates than a typical deep cycle battery. More plates in a battery equals more surface area which equals more cold cranking amp or more cranking amp. Unlike in a deep cycle battery where we want reserve capacity per amp hour, in a starting battery we're interested in the amount of power that battery will deliver over 15 seconds. So, we have more plates giving us more surface area which provides a larger burst of power. 
Starting batteries, or cranking batteries, are not designed for deep discharge applications or cycling applications. Using a starting battery in a deep cycle application will usually greatly shorten the length of the batteries life. They're not designed for cycling becausethe plates are typically thinner than in this deep cycle battery and there's a different paste in the active material in the plate that's going to help adhere that plate structure better. 
So for more information on cranking batteries, watch the video here..