Marine Cranking Amps (MCA)This is the number of amps a battery can deliver at 32degrees fahrenheit for 30 seconds, and maintain at least avoltage of 1.2 volts per cell. This differs from cold crankingamps which are measured at 0 degrees fahrenheit.
Reserve Capacity (RC)This is the time, in minutes, for which a battery will deliver 25 amperes at 80 degrees fahrenheit. This represents the time which the battery will continue to operate essentialaccessories in the event of alternator or generator failureor while the key is off.
Ampere Hour Rating (Reference Rating)This is the number of amps which a battery can deliver for a20-hour period. This test is also referred to as the 20-hourrate. The larger the ampere hour rating, the more power thebattery can deliver over time.
It’s Time To Replace Your Battery When...
• You had to jump start your battery• The battery can barely turn the starter over• Lighting and electronics dim or go out when starting• The battery will not hold a charge• The battery becomes submerged• The battery discharges frequently between use• You buy a used boat