Car battery types explained. We look at how to choose the right battery for your car. We discuss the difference between AGM, EFB and calcium batteries.
What is an AGM battery?
AGM batteries aren't your usual everyday, conventional type of cell. AGM stands for "Absorbent Glass Mat" and denotes the internal workings and active materials of these types of car batteries.
AGMs differ because, unlike standard batteries, the electrolyte liquid, better known as battery acid, is absorbed into the glass mats housed in the cell. On the other hand, standard batteries have their sulphuric acid floating loosely around rather than being absorbed.
Why would I need an AGM battery?
As motoring technology advances, the strains put on their power units and systems grow more intense. Absorbed glass mat batteries are therefore designed to handle these higher starting power demands.
An example of where AGM batteries are especially useful is in vehicles with Stop-Start systems. We can find this technology in most modern cars, and it requires a battery that can produce a lot of power.
Vehicles that contain a Stop-Start system will cut their engines when they come to a stop, rather than idling and continuing to burn fuel and produce harmful CO2 emissions.
These systems are therefore incredibly useful, cutting down on your emissions and saving you fuel. But the smooth transition from cutting out to starting again is made possible only by the power provided by the AGM battery.
These AGM batteries are also safe to be installed within the car's interior to run the various accessories, given that they do not produce harmful gases into the air.
Some AGM batteries are also dual-purpose and can power accessories and start your car's engine. If an AGM battery powers your vehicle, you must replace it with the same power supply to ensure your car remains in good condition.
Advantages of AGMs
There are several advantages to powering your car with an AGM:
~ The design of AGMs is a better match to modern charging systems.
~ AGMs produce more amp power compared to the same size of calcium battery, meaning they can power car electrics far more efficiently.
~ These batteries are entirely sealed in their casing, meaning they are entirely maintenance-free.
~ Deep-cycle batteries can be installed safely within the passenger space of vehicles, given that they are sealed and do not emit harmful gasses.
~ They can produce enough energy to be dual-purpose, powering both the car's engine and its starting, lighting and ignition.
What is an EFB battery?
Aside from AGMs, EFBs or an "Enhanced Flooded Battery" can also be used in cars that have Start-Stop systems. These batteries are not the best way to power these systems, but they are used as a standard power source.
EFBs are wet-filled and operate similarly to other flooded batteries. However, they are better suited for enhanced cycle capacities and have enhanced charging acceptance. EFBs can recover far quicker than other batteries, which is useful as they are most often required to handle difficult, cyclic, Start-Stop uses.
Does my car need an EFB battery?
The only reason you should fit an EFB battery into your car is if it is currently running on the same type of power source. Of course, vehicles with Stop-Start systems use these types of batteries.
However, they may also use AGM batteries. Therefore, if you are unsure what type of battery your car requires, you should check with a qualified engineer or mechanic before ordering a replacement.
Both AGM and EFB batteries are designed for the strenuous cycling of Stop-Start systems in vehicles, as they are durable enough to undergo the strain of constantly powering the engine.
Therefore, owners of cars containing these batteries do not need to worry about the impacts of their vehicle on the battery. But this also means that it is essential that you replace these batteries with ones of similar durability. Standard car batteries will not be powerful or reliable enough to cycle, continuously providing power to your engine.
What is a calcium battery?
Another form of a cell is a Calcium battery, also known as a valve-regulated, lead-acid battery.
These contain lead plates surrounded by the electrolyte liquid - or battery acid - and when they react with one another, they create a chemical reaction that charges the battery terminals.
The advantages of calcium batteries over AGM or EFB batteries are that they can operate under extreme weather conditions and at higher charge rates.
While AGMs and EFBs are more durable when cycling, calcium batteries provide a better power source for high-performance vehicles. Therefore, car manufacturers are using them more and more when their vehicles need higher power output for their engines and car accessories.
Does my car need a calcium battery?
As with cars that AGMs or EFBs power, those that are powered by Calcium batteries should also replace their cells like-for-like with the same lead-acid batteries, however, if you want to upgrade your cycling power or battery durability, you can also replace your Calcium battery with an AGM or EFB.
Replacements like this are considered an upgrade, given the better reliability and cycling capabilities offered by AGM or EFB cells.
How to choose the right battery?
When you need to get your car's battery replaced, there are several factors you need to consider when selecting the right one. These factors include the battery's voltage, current CCA and CA.
Voltage and Current
The voltage of a fully charged car battery should be around 12.6Volts. This tells you the amount of energy that the battery cell has stored inside of it. On the other hand, the current is the rate at which the energy flows from the battery to the object it is powering.
A battery's current is measured in amps. Calcium batteries are the most common energy source used in Indian-manufactured cars. Again, these cells contain lead plates surrounded by an electrolyte liquid. This liquid is made up of 2/3 water and 1/3 sulphuric acid. The chemical reaction between the lead plates and electrolyte mixture creates a voltage of around 12.6V.
CCA and CA
The CCA and CA of your car battery are also things you will need to consider when buying and replacing your current power source.
CCA stand for the Cold Cranking Amps rating. This measures the number of amps the battery can provide for 30 seconds at a temperature of -17ºC. Most cells have CCA ratings of 350, 450 or 600 CCA.
CA, on the other hand, is the Cranking Amps rating. This measures the number of amps the car battery produces for 30 seconds while at a temperature of 0ºC.
These ratings vary given that different batteries produce different currents, and the higher the CCA rating your car battery has, the easier it will be to start the engine.
How to get the most out of your car's battery
Now that you know all about the different types of car batteries, here are a few tips for getting the most from them in your car:
~ When replacing your car battery, make sure you replace it with one that is the right size. You can find this measurement in your car manual. Installing a battery that is too large for your car will cause your electrical components to troubleshoot.
~ When buying a new battery, always check the voltage reading with a multimeter before making a purchase.
~ Do not install used batteries into your car. This can be dangerous for both yourself and your vehicle.
~ If your car is struggling to start, check that your battery connections are all connected and if the terminals have oxidized, clean them.
~ Check the battery connections regularly.
~ Always keep a portable charger or jump cables in your car in case your battery suddenly fails.
Looking spare car parts? Visit Our Online Shop for UK delivery.