Testing your car battery is something you should do periodically. Having a healthy car battery and alternator protects your electrical system from failures. Car battery maintenance is regular car maintenance.
When testing a car battery with a multimeter, the car battery voltage should have readings of 12.6 Volts or higher. If the car is running, the car battery voltage should measure between 13.7 to 14.7 volts.
This is a complete beginner’s guide for car batteries. We’ll talk about car battery voltage charts, car battery amps, car battery types, etc…
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How Many Volts Is A Car Battery
Checking whether your car battery is working properly is an easy task that any car owner can do. You don’t need to know anything, you just need a measuring device, a multimeter. This simple device measures the voltage of a car battery.
The multimeter will show the current voltage of the car battery. No matter the type of car battery, a healthy car battery charges at 12.6 Volts or higher. When the car is running, the battery should be charging somewhere between 13.7 Volts – 14.7 Volts.
Most of the time, these readings will tell you how many volts are in your car battery and whether it’s okay.
[Related Article: How Long Does A Car Battery Last]
Car Battery Voltage Chart
This chart will help you read multimeter measurements better. Ideally, you want your car battery to always be at 80%-100% charge. That means the car battery readings you are looking for are 12.42 V – 12.7 V when the engine is not running. [Source]
Weaker readings are acceptable only if you forgot your headlights on. Or, if it’s freezing cold outside and you haven’t started your car in a while. However, once you go for a drive, and the battery charges up. The state of charge should go back 80% – 100% with a turned-off engine.
Keep in mind, 10.5 V is enough to start the car. So, your car battery can be at 0% status charge but still start.
When the engine is running, the multimeter readings will tell you whether the alternator is charging the car battery. With the engine is on, 14.0V – 14.8V measurements are acceptable. Readings like 13.2 V – 13.4 V means your car battery should be checked out. Anything below that means you need to change the battery.
Car Battery Amps
All car batteries are 12 V batteries, so mix-ups with the voltage can’t happen. What some beginners get wrong are the ampere ratings. These ratings can tell you the capacity of the battery, and how quickly the battery can charge.
Just like any battery, not just car batteries, the size determines the capacity of the battery. The thing is, the bigger the battery is, the more space there is for cells. Newer car models have bigger batteries but most batteries have a capacity of 550 to 1000 amperes.
The capacity of the battery is not that important though. What matters when choosing a battery are the cranking amps(CA) and the cold cranking amps(CCA). These amp ratings tell you how easy it is to crank the engine.
The CA tells you how many amps the battery can deliver in 30 seconds at a temperature of 32° F. The CCA tells you many amps the battery can deliver in 30 seconds at a temperature of 0° F. [Source]
It depends on where you live but most of the time, the cold cranking amps are more important. If the CCA is high, then the battery can crank the engine easily even in freezing temperatures.
Car Battery Ampere Hours Ratings
You will also find that the car battery manufacturer lists a chart of the ampere-hours(Ah). These ratings tell you how much amperes the battery can deliver without being charged. For instance, a car battery at 80Ah, 4 amps for 20 hours, or 8 amps of power for 10 hours, etc…
The car battery Ah chart also tells you how the battery capacity deteriorates over time.
Car Battery Types
In commercial cars, you will mostly find three types of car batteries. The most common car batteries are wet cell batteries, VRLA batteries, and lithium-ion batteries. Wet cells batteries have been dying for quite some time because they require the most maintenance. 2000’s cars have VRLA batteries, and electric vehicles use lithium-ion batteries.
If you don’t know what type of car battery you have, chances are, it’s a VRLA. If it’s an EV, you have lithium-ion batteries. However, there are 5 more car battery types out there.
- Wet Cells Batteries
Also known as flooded lead batteries. The battery you find in old pre-2000’s cars. These are really cheap to buy and also store power easily. The only bad thing about wet cells batteries is the maintenance like watering and cleaning. They are made out of an electrolyte solution that needs to be watered periodically. Also, the batteries go bad if dropped below 50% charge. - Valve Regulated Lead-Acid Batteries
These car batteries(VRLA) are just like wet cells batteries. The only difference is that they are sealed meaning they do not spill when tipped over. Also, VRLA batteries do not need to be topped off. So, they are effective and don’t need maintenance. - Lithium-ion Batteries
Lithium-ion car batteries are used for electric cars or hybrids. These are more expensive than the other common car batteries but are worth it in the long run. Lithium-ion batteries are smaller, able to store more power, and charge up really quickly. This is what makes them perfect for electric vehicles. - AGM(Absorbent Glass Mat Battery)
AGM car batteries are advanced VRLA batteries that can support a higher demanding power supply. These batteries were made because of the superior electrical systems of modern vehicles. Modern cars have electrical systems that demand more power. The AGM car batteries are corrosion-resistant, sealed, and need no maintenance. - Gel Cell Batteries
Also known and dry cell batteries, meant to be an improvement over the flooded lead batteries. Gel cell batteries survive vibrations more. Because there is silica gel added to the electrolyte solution, the acid doesn’t spill when the battery is tipped over. - Silver Calcium Batteries
Silver calcium batteries are sealed, require no watering, and are more resistant to corrosion. Instead of using lead-antimony plates, lead-calcium silver plates are used. This makes silver-calcium batteries more durable and corrosion-resistant. - NiMH Batteries
Nickel-metal hydride batteries are not that common. Mostly used in hybrid vehicles. Their big disadvantage is that they are prone to self-discharge. Although they last the longest by far, the self-discharge and the temperature make them undesirable. - Deep Cycle Batteries
You will find deep cycle batteries mostly in vehicles you use periodically like golf carts, boats, etc… Deep cycle batteries are made to last long while providing power to an electric system that’s not that demanding.
How Much Does A Car Battery Weigh
Not all car batteries weigh the same. Some are heavier, some are lighter. The weight depends on the size of the battery, the solution inside, and the charge status. For instance, lithium-ion batteries weigh less than lead-acid batteries.
Most car batteries weigh around 20 to 60 pounds. The general rule is, the higher the cranking amps, the heavier the battery is. Car batteries manufacturers list the weight of the battery in the specification.
As mentioned earlier, the size of the battery determines the capacity of the battery. So, batteries that provide more power are usually heavier. Keep in mind though, the materials used for making the battery matters too.
Related Questions And Other FAQs
Is 11.9 Volts Enough To Start A Car
Although 11.9 V means the car battery is not in a good condition, it should be able to start the car. A car battery should be able to crank the engine even with 10.5 V. Ideally, you want your car battery to be at a full charge when starting a car, that is, 12.42 V to 12.7 V.
What Voltage Is Too Low For Car Battery
While the engine is not running, any readings below 12.06 V means that there is something wrong with the battery. When the engine is running, any readings below 13.7 V are too low for a car battery.
