Some Useful Battery Terminologies

• Cold Cranking Amps (CCA) : Cold cranking amps (CCA) is a measurement of the number of amperes a battery can deliver at 0 ° F for for half minute or 30 seconds without dropping voltage below 7.2 volts. So a high CCA battery rating is particularly important in starting battery applications, and also in cold weather.Though not particularly important measurement for Deep cycle batteries, but still it is the most commonly 'known' battery measurement.
• Ampere Hour (AH) : An amp hour (AH) is a rating terminology commonly used for deep cycle batteries. The standard rating is an Amp rating taken for 20 Hours. What this means, say for a 200 AH rated battery is this: Draw from the battery for 20 hours and it will provide a total of 200 amp-hours. That translates to about 10 amps an hour 10 x 20 = 200.However,it is important to note that no linear relationship exists between total time of discharge and the load applied to the battery. The realized capacity of the battery decreases with the increase in load on the battery.This means if you discharged that same 200 AH battery by a 200 amp load, it will not give you one hour of run time. On the contrary, the perceived capacity of the battery will be that of 128 Amp Hours.
• Specific Gravity of Battery Electrolyte : The term specific gravity describes the ratio of the density of electrolyte to the density of water.Specific gravity of battery electrolyte is an accurate & direct measure of state of charge of a battery cell.The greater the specific gravity of the electrolyte the greater the state of charge. To properly monitor your battery over it entire life span,it is advisable is to regularly take and record specific gravity readings.Specific gravity is temperature dependent and may lead to errors in readings recorded when temperature is either too hot or too cold.