Invented in the late 1800s, lead-acid batteries come in a wide range of performance to work with many kinds of vehicles. You can compare them based on their rated lifetime and their electrical capacity. 

 

Lead-acid batteries, while very durable and rugged, have limited lifetimes. Most car batteries sold in the United States are rated for 60 to 84 months.

 

Temperatures well below freezing slows a battery's chemistry and lowers its current. At temperatures over 100 degrees, a battery will self-discharge at a faster rate. If it's left unused for several days at this temperature, it will have less charge.

 

A standard way of comparing car batteries, cold-cranking amps (CCA) measure the electrical power a battery can deliver in a 30-second burst before it drops below 7.2 volts. This is tested at zero degrees Fahrenheit. A typical car battery may be rated at 750 CCA.

 

Reserve capacity rates a car battery by how long it can handle a 25-amp load at 80 degrees Fahrenheit before the voltage drops below 10.2 volts. A typical, fully charged battery can maintain this load for 90 minutes or longer.

 

Batteries for cars and trucks are designed to put out a lot of current for a short period of time. Running a car battery to under 20 percent of its capacity ruins it. Marine and golf cart batteries, called deep-cycle batteries, supply less instant current but can be discharged more deeply.