Marine Starting Battery - Gas Inboard Engine or Outboard Motor
The starting batteries for gasoline Inboard or Outboard motors must consistently deliver high cold cranking amps (CCA), operate in high and low temps and withstand vibration. With the engine off, High-Cycle Reserve Capacity (RC) is required to support added electronic equipment such as GPS, depth finders, radios, navigation lights, bilge pumps, live wells, etc. The engine alternator is the sole charging source for the starting batteries. Maintenance-free spill-proof batteries are highly desirable in marine applications.
Starter battery specifications: Cold Cranking Amps (CCA); the amps a 12V battery can discharge for 30 seconds at -18°C / 0°F while maintaining its voltage above 7.2 volts. Because lead-acid batteries produce more energy at higher temperatures, we also rate marine batteries in Cranking Amps (CA), similar to CCA but measured at 0°C / 32°F and Marine Cranking Amps (MCA), similar to CCA but measured at 27°C / 80°F
Higher cranking power is required for cold temperatures, diesel engines, or high-compression gas engines where high cranking voltage must be maintained for the fuel ignition systems to function. This requires maximum Amp Hours (AH) or Reserve Capacity (RC): Minutes a battery can maintain a load of 25 amps before it drops to 10.5 volts (at 27°C / 80°F).
Dual-purpose batteries must consistently deliver reasonable cold cranking amps (CCA), operate in high and low temps and withstand vibration. With the engine off, Reserve Capacity (RC) is required to support moderate electric loads such as electronic equipment, radios, house lights, bilge pump, small inverters, etc. From low to high, dual-purpose batteries can be designed with micro-cycle (17.5% Depth of Discharge - DoD) or high cycle (30% Depth of Discharge - DoD) life characteristics. Typically, the higher the cycle life ability, the lower the CCA rating will be in a dual-purpose battery. A battery with high CCA, High Reserve Capacity “and” long life should be viewed with suspicion.
Lead-acid battery failure is most commonly caused by acid stratification, extreme temperatures and destructive vibration. Acid stratification naturally occurs in flooded lead-acid batteries and leads to a decline in capacity and charge acceptance. AGM technology and acid mixing technology for flooded lead-acid starting batteries will mitigate acid stratification.