Electrolyte type
Car batteries include
lead-acid (SLA), advanced
lead-acid (EFB),
glass fabric (AGM),
gel (GEL),
lithium-ion (Li-Ion) and
lithium iron phosphate (LiFePO4). More details about them:
— SLA (lead-acid). In a broad sense, the vast majority of modern car batteries are lead-acid, because... their design is based on a combination of electrodes made of lead compounds and an electrolyte, the role of which is played by sulfuric acid diluted with water. Specifically, in this case we mean the classic type of batteries, which use ordinary liquid electrolyte. Their widespread use is due to their simplicity of design and low cost, combined with good capacity and inrush currents (see below), as well as resistance to low temperatures (compared to other types of batteries).
— EFB (lead-acid). An improved subtype of lead-acid batteries with a longer service life, a high degree of safety and a virtually maintenance-free design. The abbreviation EFB stands for Enhanced Flooded Battery, which means “Enhanced Flooded Battery.” A distinctive feature of EFB technology is thick plates made of pure lead without any impurities. The positive plates in the battery design are wrapped in special “packages” made of microfiber, which absorbs and holds liquid electrolyte. As a result, inten
...sive shedding of the active substance is prevented and the sulfation process is significantly slowed down when the battery is deeply discharged. And due to the homogeneous structure of the electrolyte (it mixes during the natural movement of the car), the overall service life of EFB lead-acid batteries increases and the charging speed increases.
— AGM (fiberglass). A type of lead-acid battery, also known by the abbreviation AGM. The main feature of the design is described by the name itself: in such batteries, the space between the plates is filled not with liquid, but with fiberglass - microporous plastic, which is impregnated with the electrolyte itself (an aqueous solution of sulfuric acid). This design has a number of advantages over the classic one: for example, AGM batteries do not require maintenance (see “Maintenance”) and practically do not emit gases when charging (the resulting oxygen and hydrogen recombine inside the battery itself), are resistant to shaking and are well suited for start systems -stop (see "Start-stop support"). Their disadvantages are high sensitivity to increased voltage when charging, the need for a special charger (regular ones do not fit well), and also their high cost.
— GEL (gel). One of the subtypes of lead-acid batteries in which the electrolyte is not liquid, but is condensed to a gel-like state. This design provides a number of advantages compared to the classic version (see above): a greater number of charge-discharge cycles (and therefore a longer service life); minimum leakage of electrolyte and associated gases; no need for maintenance (see “Maintenance”); resistance to deep discharges and temperature fluctuations, etc. On the other hand, GEL batteries are significantly more expensive.
— Li-Ion (lithium-ion). Lithium-ion technology was originally used in batteries for portable gadgets such as mobile phones, but such batteries are increasingly used. The first type of transport to use Li-Ion technology was motorcycles. The advantages of such batteries over more traditional varieties include smaller dimensions and weight, the ability to produce high starting currents and be charged with high currents (the latter significantly reduces charging time), as well as a large number of charge-discharge cycles and a long shelf life. In addition, Li-Ion batteries contain a minimum of harmful substances, do not use acids or heavy metals, and some models are even positioned as absolutely harmless to the environment. The main disadvantage of lithium-ion batteries is their very steep price.
— LiFePO4 (lithium iron phosphate). Such batteries are actually a modification of lithium-ion batteries (see the corresponding paragraph), developed to eliminate some of the shortcomings of the original technology. They are notable, first of all, for their high reliability and safety: the likelihood of a battery “exploding” when overloaded is reduced to almost zero, and in general LiFePO4 can cope with high peak loads without any problems. In addition, they are quite resistant to cold and maintain operating voltage almost until discharge. The main disadvantage of this type is its slightly smaller capacity.Battery capacity
The electrical capacity of a battery, in other words, the amount of energy stored by a battery when fully charged. The capacity value is expressed in amp-hours and indicates the number of hours during which a fully charged battery will be discharged to the minimum allowable charge, delivering a current of 1 ampere to the load. For example, a capacity of 40 Ah means that the battery is capable of delivering a current of 1 A for 40 hours, or 2 A for 20 hours, etc. In fact, a more capacious battery gives more attempts to start the engine, and is also able to work longer at a low load (for example, when powering a car audio system).
The capacity requirements for different transport types differ markedly. So, in motorcycle batteries, it rarely exceeds 20 Ah, the average value for passenger cars is 40-80 Ah (but there are options for 100 Ah or more), and for heavy equipment like buses, an acceptable capacity starts somewhere from 100 Ah. The optimal value of the battery capacity is often indicated by the manufacturer in the characteristics of the vehicle, and when choosing a model by capacity, you should focus primarily on these figures.
Starting power (EN)
Battery starting power measured according to EN standard. According to this standard, the starting power is the maximum power that a battery at an electrolyte temperature of -18 °C can produce for 30 s without the voltage dropping below a certain level (for standard 12 V batteries - not lower than 7.2 V). The term “starting” appeared because this mode of operation is similar to starting an engine, when the battery has to supply high power power to the starter for a short time.
The recommended starting power value is generally related to the weight category of the machine: the heavier it is, the more powerful the power is usually needed to start. And many manufacturers directly indicate recommended values in the characteristics of a particular vehicle model. If the battery is purchased as a replacement, then the general rule is this: its starting power should be no less than that of its predecessor.
Note that in practice there may be designations for starting power according to 3 more standards: SAE (USA), DIN (Germany) and TU (GOST 959-91). The first is almost identical to EN, and DIN and TU are quite easy to convert to EN and vice versa: they are similar to each other, and each of them gives a number approximately 1.7 times smaller than NE. That is, for example, to replace a 200 A battery according to the specifications, you should look for a model with a power of at least 340 A (200 * 1.7) according to EN.
Start/Stop support
The possibility of using the battery in cars equipped
with a start-stop system.
The start-stop system was created to save fuel and reduce harmful emissions in a modern city, when cars are often forced to stop at traffic lights and in traffic jams. In such cars, a simplified procedure for turning off and starting the engine for short stops is provided: for example, standing at a traffic light, the driver turns off the car by pressing a button, and when the green light turns on, he starts the car by simply pressing the clutch pedal. This provides significant fuel savings, but repeated starts significantly increase the load on the battery — conventional batteries can wear out in a matter of days. Start-stop support allows the battery to work effectively in multiple starts, maintaining its characteristics for a long time.
