Comparing Apples to Apples, Cold Cranking Amps, Marine Cranking Amps and Reserve Capacity

Now that we have established what "group size" means, we will move to the next decision that you must make when purchasing a battery.  The first thing you will notice as a consumer is the wide range of prices there are for the same group size battery.  In order to make an informed decision you must know how to compare the different brands to find the best value.  First we will look at starting batteries.  Starting or cranking batteries are designed to give a short burst of energy to start your vehicle, boat, lawn tractor, etc.  The rating you should be looking for on this type of battery is the Cold Cranking Amps (CCA).  Cold Cranking Amps (CCA) is a measurement of the number of amps a battery can deliver at 0 degrees F for 30 seconds and not drop below 7.2 volts.  Batteries of the same group size can have very different CCA ratings, this is where you as a consumer need to make sure you are comparing apples to apples before just choosing the least expensive battery.  While it may fit your application in physical size, it may not be enough CCA for your application which could ultimately lead to premature failure.

The next type of batteries we will look at is the marine starting and deep cycle battery.  Here again, you will find an array of batteries that look the same physically but are very different!  When making your purchase of a marine battery you want to look for the Marine Cranking Amps (MCA) and the Reserve Capacity (RC).  Marine Cranking Amps (MCA) are measured at 32 degrees F.  The reserve capacity (RC) of a marine battery is the number of minutes a fully charged battery at 80 degrees F will discharge 25 amps until the battery drops below 10.5 volts, for example:  your battery has a RC of 145 minutes @ 25A and your accessories (lights, gps, depth finder, livewell/baitwell pumps, etc.) add up to a 25A draw, in this situation with a new battery you will get 145 minutes of run time until your battery is discharged.  If your draw is less than 25A your run time will increase and likewise if you draw more than 25A your run time decreases.

Just like with your starting batteries you must make sure to compare apples to apples here as well.  Just because a battery "looks" the same doesn't mean it is.  You will be saving yourself time and money in the long run by comparing the MCA and RC of different batteries before just buying "one that fits."  If you're looking for the best value, your decision making regarding your batteries is not done yet!  In our next article, "Choosing Value over Price, Absorbed Glass Mat (AGM) vs. Wet Cell (Flooded) Batteries", we will walk you through the process of deciding which is right for you!

Here at Treasure Coast Battery & Alternator we know choosing the proper battery can be a daunting task to say the least, our team of battery experts can help take the stress out of that process.  We carry a complete line of Exide Auto and Marine batteries, Crown Golf Cart batteries and Northstar AGM batteries with pure lead technology.  Please don't hesitate to contact us with any battery related questions you may have!

David Jouppi - Manager
Treasure Coast Battery & Alternator