COLD-CRANKING AMPERES (CCA)
The battery's primary function is to provide energy to crank the engine during starting. This requires a large discharge in a short time. The CCA Rating specifies, in amperes, the discharge load a fully charged battery at 0 ̊F (-1 7.8 ̊C) can deliver for 30 seconds while maintaining a voltage of at least 1.2 volts per cell (7.2 volts total for a 12-volt battery). Batteries used on various Toyota vehicles have CCA ratings ranging from 350 to 560 amps.
RESERVE CAPACITY (RC)
The battery must provide emergency energy for ignition, lights, and accessories if the vehicle's charging system fails. This requires adequate capacity at normal temperatures for a certain amount of time. The RC Rating specifies, in minutes, the length of time a fully charged battery at 80 ̊F (26.7'C) can be discharged at 25 amps while maintaining a voltage of at least 1.75 volts per cell (10.5 volts total for a 12-volt battery). Batteries used on various Toyota vehicles have RC ratings ranging from 55 to 115 minutes.
AMP-HOURS (AH)
The battery must maintain active materials on its plates and adequate lasting power under light-load conditions. This method of rating batteries is also called the 20-hour discharge rating. Original equipment batteries are rated in amp-hours. The ratings of these batteries are listed in the parts microfiche. The Amp-Hour Rating specifies, in amphours, the current the battery can provide for 20 hours at 80 ̊F (26.7 ̊C) while maintaining a voltage of at least 1.75 volts per cell (10.5 volts total for a 12- volt battery). For example, a battery that can deliver 4 amps for 20 hours is rated at 80 amp-hours (4 x 20 = 80). Batteries used on various Toyota vehicles have AH ratings ranging from 40 to 80 amp-hours.
POWER (WATTS)
The battery's available cranking power may also be measured in watts. The Power Rating, in watts, is determined by multiplying the current available by the battery voltage at 0 ̊F (-1 7.8 ̊C). Batteries used on various Toyota vehicles have power ratings ranging from 2000 to 4000 watts.