Will driving a car fully recharge a battery?
There are a number of factors affecting an alternator's ability to adequately charge a battery. The greatest factors are:
- How much current (amps) from the alternator is diverted to the battery to charge
- How long the current is available (drive time)
- Battery temperature
- Battery age
Generally, running the engine at idle or short stop-and-go trips, during bad weather at night, will not recharge the battery effectively.
In the following situations, the alternator will not adequately recharge a battery:
- The battery is drained because an interior light was left on in the car for 18-24 hours.
- The battery is drained because the vehicle has not been driven for a month or more.
- The car is only driven at 60 km/h (35 mph) to a nearby store and back 2 or 3 days a week.
What are cold cranking amps (CCA)?
The battery's Cold Cranking Amps (CCA) is an important measure for good cranking ability in cars, trucks and boats. CCA is the amount of current or amps a battery can provide at -18° C (0° F) for a 30-second duration until the battery voltage drops to unusable levels. The rating is defined as the current or amps a car battery can deliver for 30 seconds and maintain at least 1.2 V per cell (7.2 V for a 12-V battery) at -18 °C (0° F). Refer to your application guide for the vehicle, and follow the recommended CCA rating for that vehicle's engine and features (ampere-hour rating, optional equipment, etc.).
For example, a 12-volt battery with a 650 CCA rating means the battery will provide 650 amps for 30 seconds at -18° C (0 °F) before the voltage falls to 7.20 V for a 12 V battery. So in extremely cold temperatures, the higher CCA level is required to crank your engine. In addition, as more cranking power is used, the amount of battery power available decreases.
Specialty batteries - What is the difference?
These batteries have starting power, plus the ability to power the many creature comforts in today's boats and RVs. In addition, these batteries have thicker lead plates and typically have both threaded posts as well as the standard SAE automotive posts to connect to the vehicle's battery cables.
Golf Cart Batteries
Unlike car batteries, golf cart batteries don't need starting ability. Instead, they need to be able to power your cart with long periods of time between charges.
Lawn and Garden Batteries
Designed to work as hard as you, Lawn and Garden batteries can power up your mower week after week. They're also designed to tolerate the high vibration created in most mowers which helps them last longer.
How do I know when it is time to replace the battery in my car?
There may be little or no warning. However, if any of the following happen, your battery should be tested immediately:
- Motor has difficulty cranking over
- Battery indicator light on the instrument panel stays lit for extended periods after starting. This could also be a mechanical issue (possible alternator) and should be checked by a professional mechanic.
- Headlights dim when the engine is idling
- Clock starts to lose time after the vehicle sits unused for several days
Note: To maximize the vehicle's battery/charging system service life and performance, it is recommended a vehicle's battery and charging system be tested at least semiannually or every time the oil is changed.