.:
battery rating terminology

CCA

Defined as Cold Cranking Amps The number of amps a battery can
deliver for 30 seconds at 0°F before
the voltage drops to 1.20 volts per
cell (7.20 volts for a 12 volt
battery).

MCA 
Defined as Marine Cranking Amps (sometimes called CA)
The same test as CCA except at 32°F. 
HCA 
Defined as Hot Cranking Amps
The same test as CCA except at 80°F. 
Ah rating 
Defined as amperehour rating capacity 
may be a 10hour and/or 20hour rate of
discharge A 12 volt battery rated
at 50Ah for the 10hour rate of
discharge can supply 5amps for 10 hours
before its voltage drops to 10.02 volts.
This does NOT mean that it
can supply 50amps for 1 hour.
Using the Odyssey PC1500
battery data.  Its advertised 10hour rating is 62Ah

The data shows it can supply 6.2 amps for 10 hours
 The data shows it can supply 60 amps for 45 minutes, NOT 62 amps for 1 hour.

Reserve Capacity 
Refers to the number of minutes a
battery can supply 25 amps at 80°F
before its voltage drops to 10.50 volts
(for a 12 volt battery). 