How to choose a car battery

How to choose a car battery

If you want to be sure you can start the engine of your car regardless of the weather, you need to keep the battery in a good working condition. Its average life expectancy is 5–7 years. It is advisable to replace the component at the end of this period. Read on to find out which battery types are the most demanded and efficient these days. We will also tell you about the things you need to consider when choosing a car battery.

 Types of car batteries 

Wet (Wet Cell Battery)

Their electrodes consist of plates covered with sponge lead or lead dioxide. A solution of sulphuric acid is used as an electrolyte. Such batteries are the most common, inexpensive and, compared to other types, they are less sensitive to overcharge and voltage variations in the vehicle mains. But deep discharge is very dangerous for these batteries: it causes plate sulfation. Regular under-charging, which happens during short-distance trips in the cold season, is also not advisable. The electrolyte can freeze at low temperatures. Moreover, it evaporates. That is why, if your battery is not labelled as maintenance-free, you need to monitor electrolyte density in it and dilute it with distilled water from time to time.

Wet (Wet Cell Battery)

EFB (Enhanced Flooded Battery)

They differ from usual lead-acid batteries by plate configuration – a special mesh material is applied on their positive sides. It serves to prevent lead sponge disintegration and plate sulfation, thus increasing battery lifespan. These batteries feature better performance, charge faster and can restore up to 100% of initial capacity after deep discharge. They also have higher сold cranking amps. They are a bit more expensive than standard lead-acid batteries but are more efficient and serve longer. They maintain operability at the temperatures as low as −50 °С. But such power sources are incompatible with vehicles with the regenerative braking system.

EFB (Enhanced Flooded Battery)

AGM (Absorbent Glass Mat)

Their key difference from the standard ones is a fibreglass layer which absorbs liquid electrolyte. Such batteries are charged 2–3 times faster than the regular ones. Despite having the same sizes as other types, their capacity is significantly higher. They are also more resistant to vibrations. Their disadvantages include a higher price. Over-charging is dangerous for this type of batteries, as well as storing in fully discharged condition.

AGM (Absorbent Glass Mat)


Like those listed above, they belong to lead-acid type, but electrolyte in them was made immobile and gelled by adding silicon dioxide. This increases battery life expectancy, sometimes it can reach 10 years. Such batteries are resistant to deep discharge: they withstand up to 400 cycles, while the standard wet-cell ones – only from 20 to 30. Moreover, they feature high cranking amps, 2–2.5 times higher than usual. Due to this, you can start the engine without any difficulties even in the coldest winter. Also, such batteries are charged faster, which helps to avoid problems caused by frequent short-distance trips. They have an extremely small self-discharge rate but are expensive. When using them, it is very important to monitor the condition of electrical equipment, especially the alternator voltage regulator. Even small overcharge causes irreversible changes in electrolyte contents and is detrimental for this type of batteries.

Gel Battery
Important note: Before purchasing a battery of a type that differs from the standard one for your car, check the vehicle manual to make sure this is allowed by the manufacturer. Using an unsuitable battery is dangerous!

 4 parameters to consider when choosing a battery 


It is measured in ampere-hours. This parameter shows the current a battery is able to supply during 20-hour discharge with voltage above 10.8V. For example, a 72 A⋅h battery has sufficient capacity to supply a current of 3.6A for 20 hours. The more powerful the car is, the higher capacity battery it requires.

Cold cranking amps (CCA)

This value is measured in amperes. It shows the max current the battery can supply in the first seconds to start the engine at −18 °C. This value defines if the battery has enough power to start the engine in winter. This parameter for passenger cars should be over 255 A for petrol engines and over 300 A – for diesel ones.


They should correspond to the sizes of the standard equipment. Otherwise, you may face difficulties installing the battery. For instance, batteries made for American cars have terminals on the side, unlike those for European cars with terminals on top. Moreover, they have an inner thread.


It can be normal or reversed. In the first case, the positive terminal is located on the left, in the second – on the right. Normal polarity is usually marked with 1 or L sign, reversed – with 0 or R. Polarity of a new battery should be the same as of an old one, otherwise, the cable for connection will have insufficient length.

Important note: Choose products of well-known brands, such as Bosch, Varta, Vemo, Exide, Ipsa, Energizer, Herth+Buss Elparts, Magneti Marelli. Their products feature the highest quality and, with proper maintenance, will serve you for years to come.


A stable work of electronic equipment and the ability to start the engine directly depend on the condition of a car battery. That is why it is very important to choose an item that corresponds to vehicle specifications. Information about the parameters of the battery installed as standard can be found on its casing or in the car manual. We advise you not to change the parameters of the equipment you select: this can be dangerous. Make purchases in the online shop AUTODOC: here you will find reliable products only.