Battery Definitions
To help reduce some of the confusion surrounding battery terminology, below are some battery rating definitions. Please e-mail your additions, clarifications and corrections to georgevaldes@pgwebconsulting.com. Thank you.
- Cold Cranking Amps (CCA)-
- The maximum amperage that can be discharged for 30 seconds, at 0°F, before a battery drops to unsafe levels. Used for Starting Selection.
- For example: 550 CCA (Cold Cranking Amps) will deliver 550 amps for 30 seconds, at 0°F.
- Marine Cranking Amps (MCA) -
- Similar to CCA except measured at a higher temperature (than CCA).
- AMP/Hour Rating -
- Battery capacity. How many AMPS for how long before full discharge.
- For example: 5 AMPS for 20 hours = 100 AMP/hours to full discharge.
- Reserve Capacity (RC) -
- Amount of time that a 25 AMP draw will discharge a battery.
- Cycle Life -
- How many times a battery can be taken to full discharge (i.e. recharged-discharged-recharged) before failure.
- Deepcycle (DC) -
- More Cycle Life, greater Reserve Capacity. Battery has material skeletal structure difference. Can be used for cranking.
- Series Connection
- Increase voltage
- Parallel Connection
- Increase Current (AMP/Hours)
- Over Charging -
- Damages batteries. Evaporation exposes and buckles plates. Causes oxides on plates to shed. Reduces capacity.
- Over Discharging -
- Shortens battery capacity. Creates sulfation to restore battery to almost normal. Charge the battery slowly 2-4 AMPS until cells are gassing freely. Gel Batteries may NOT recover!
- Hydrometer Readings -
- - Marine battery full charge = 1.255 - 1.265 at 80°F.
- There should be no more than .025 difference between cells.
- Pure water = 1.000 Specific Gravity.
- Concentrated Sulphuric Acid = 1.835 Specific Gravity.
Percent of
charge |
Specific Gravity
Range |
| 100% |
1.255 - 1.260 |
| 75% |
1.220 - 1.225 |
| 50% |
1.185 - 1.190 |
| 25% |
1.150 - 1.155 |
| 0% |
1.115 - 1.120 |
Thank-you to Steve Miller for providing this edification. Thank you to George Valdés, Sr. for reviewing and clarifying this information.
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