Your car battery provides a big jolt of electrical energy to power your lights, accessories and more. Without it, your car won’t start.
Traditional lead-acid batteries have a container filled with battery acid, positive and negative terminals. Some standard batteries have vents for airing out corrosive gases, steam or condensation (these are called wet cell or flooded batteries). Newer “low-maintenance” batteries use an alloy for the positive and negative grids that reduces water loss on charging.
Volts
A car battery is the heart of your vehicle. It provides an immediate burst of power when the engine starts, as well as providing electricity to run electrical accessories and sensors. A good battery can hold a charge for a long time, but the exact voltage of a battery can change depending on temperature and usage patterns.
A typical car battery has a resting voltage of around 12.6 to 12.8 volts, boosted slightly when the engine is running. You can test the voltage of your battery with a multimeter or voltmeter by touching the positive and negative cables on each side of the battery. However, it’s best to wait overnight for a more accurate reading. Trying to test a battery too soon can result in it ‘calcifying’, which reduces its ability to recharge and hold a charge. A calcified battery will eventually fail. The best way to avoid this is to have your battery tested regularly, often as part of routine service, or by a local auto shop.
Amps
Car batteries have different amp capacities, which determine how much power the battery can deliver on an hourly basis. The higher the ampere-hour (Ah) rating, the longer the battery can last.
A typical car battery has an Ah rating of about 40 to 50 ampere-hours, with larger vehicles like trucks using batteries with a higher rating. Other battery specifications are also important, such as Cold Cranking Amps and Reserve Capacity.
Cold weather can cause batteries to use more power, resulting in them being discharged quicker. This is because the battery’s lead sulfate crystals tend to build up in severe temperatures. Reserve capacity is another important battery specification that shows how long a battery can go without being charged. It’s measured by the number of minutes that a battery can supply 25 amperes at 80deg F before its voltage drops to 10.5 volts. Generally, older batteries tend to have lower Reserve Capacity ratings.
CCA Rating
The CCA (cold cranking amps) rating of a battery measures the amount of power it can deliver to an engine for 30 seconds at 0 degrees Fahrenheit. The requirements for CCA vary depending on the vehicle size, engine type and climate of your region.
Battery capacity declines as temperature falls, reducing the amount of electrical current it can produce and slowing down chemical reactions within the battery. This is why choosing a battery with a high CCA rating is crucial if you live in an area that experiences harsh winter temperatures.
However, it’s important to balance the CCA rating with other battery metrics like reserve capacity. Overusing a battery with a high CCA can lead to faster wear and potentially damage the internal components. It’s best to consult HBPlus Battery Specialists for guidance on which batteries are suitable for your application and climate. They’ll help you find the right combination of power and longevity.
Maintenance
The best way to get the longest life from a car battery is to drive it regularly. It also helps to remove accessories when they’re not in use and keep the battery terminals clean, as corrosion can impede electricity flow. It’s a good idea to replace broken and corroded battery base clamps and hold-down brackets, too. These can cause the battery to rattle around inside the case and contribute to early failure.
Conventional flooded lead-acid batteries and absorbent glass mat (AGM) ones recharge as you drive the vehicle, but they’ll need a boost from a charger when the car sits for long periods of time. Hooking up a battery maintainer is an alternative to replacing the battery altogether.
Most modern batteries have onboard state-of-charge indicators or battery health indicators, sometimes called “battery eyes.” They show a green symbol when the battery is charged, red when it needs distilled water, and yellow with a central dot when the battery is nearing end of life.