The question of how to choose a car battery can be approached in several ways. If you were satisfied with the previous power source, which you parted with after a long service life, you can buy exactly the same. You can also consult with friends or experts from a spare parts store. Anyway, it is advisable to be knowledgeable about basics to answer additional questions from those who have volunteered to help you, if necessary.
Capacity and starting current: the right choice is the key to success
Do you know what a car battery, a battery in a mobile phone, and even ordinary “finger” batteries from a camera have in common? Capacity is considered an important specification for any battery, since it depends on it how much energy will be spent in a certain period of time — capacity is usually measured in hours. The electric charge is measured in ampere hours or in milliampere hours.
All that is left to do when choosing a battery is only to understand how to choose the right capacity particularly for your car. If you make a wrong choice (and if the capacity is insufficient), don’t be so tragic about it, yet there may be problems with starting the engine in the cold season, in addition, there may not be enough energy for the onboard network. At the points of sale there are special tables by which you can determine which batteries are better for a passenger car, SUV and even a truck.
| Battery capacity, Ah | Vehicle | Engine displacement, L |
|---|---|---|
| 40 — 45 | Passenger city cars | 0.8 — 1.5 (up to 2.5) |
| 50 — 63 | Supermini cars with a displacement of up to 2 litres (petrol) |
1,3 — 2,0 |
| 65 — 78 | Passenger cars (SUVs, minivans) with a displacement of up to 3.5 litres (petrol) or up to 2.2 litres (diesel) | 2.0 — 3.5 (G) / Up To 2.2 (D) |
| 80 — 100 | Diesel minibuses\minivans with additional electronics | 2,5 — 4,4 |
| 105 — 110 | SUVs or premium class sedans with a displacement of 3.0 litres or more, small trucks | 3,0 — 6,0 |
| 120 — 145 | Commercial vehicles with a displacement of 4.5 litres or more, loaders with hydraulic or electric equipment | 4,5 — 8,0 |
| 180 — 190 | Commercial vehicles with a displacement of 6 litres, bulldozers, cranes, large loaders | 6 — 12 |
| 225 — 230 | Commercial vehicles with a displacement of 8 litres or more, bulldozers, cranes |
8 — 18 |
People usually have a quite popular question when choosing a battery: can I buy a battery with a larger capacity than recommended? This is permissible, besides, a battery with a larger capacity will slightly extend the safety margin in winter. It needs to be charged longer, yet the discharge time will increase accordingly. However, you should not get carried away, obviously focusing on a large capacity: the onboard network «memorises” your battery specifications, so it will not be able to fully charge a power source with a larger capacity.
The second necessary parameter for smooth battery operation is the starting current. Its importance is easy to explain even to junior pupils who do not study physics: if the starting current does not have the proper value, the car will not start. Those who are older know that the starting current is characterized by the maximum current strength that the battery gives within the minimum interval. This specification is extremely important for car enthusiasts living in regions where low temperatures are common: oil viscosity increases significantly in the cold, therefore, you need to make more efforts to start a vehicle, and this exactly has something to do with larger starting currents.
When choosing a battery for a passenger car, keep in mind that a middle segment car will need 250-270 amperes to start the engine. For diesel engines, this indicator can increase up to 300 amperes.
Size matters
This phrase is used in different situations, but in the question of which battery is better to buy for a car, it is definitely not worth neglecting. Moreover, when we are talking about size, your preferences as a car enthusiast play an important role. After all, batteries for European and Asian cars have different sizes.
Batteries manufactured in the European Union have the following dimensions:
| 40–70 А/h | 70–225 А/h |
| length: 175–242 mm | length: 278–518 mm |
| width: 175 mm | width: 175–240 mm |
| two heights: 175 и 190 mm | two heights: 175–242 mm |
Small Korean, Japanese and Chinese cars have the following standard sizes:
- length: 187–261 mm
- width: 127–175 mm
- height: 190–227 mm
Batteries for Asian cars with a capacity of 90-120 Ah have their own specific length, width and height: 306x173x225 mm. Consider this information when choosing a battery.
Choose by design
R or L, 0 or 1, straight or reverse? Don’t panic if you are asked such questions. This is about battery polarity. It is quite easy to determine: you turn the battery towards yourself, “facing” it, and if the plus is on the left, then the polarity is straight, but if the plus is on the right, the polarity of your battery is reverse. If you suddenly forgot to check which polarity you need, here is a hint for you: generally, in Russian cars it is straight (denoted by L or 1), in European cars it is reverse (R or 0). But there may be subtle aspects, so it’s better to check with the seller.
When choosing a battery by design, along with the polarity, battery mounting type is another important thing you should keep in mind. The geographical criterion is also taken into account here, and it’s the same as when choosing sizes: power sources in European cars are mainly attached with the help of special ramps on the bottom part of the casing called hold down ramps. Asian batteries have smooth cases, and the battery is attached with the help of a battery hold down that is pressed from above. It may seem like this is a trifle but your battery life may depend on this very trifle: the internal elements of a loose battery have every chance of crumbling and failing.
On all fronts
As for the rest of the parameters, when choosing a battery for a passenger car you need to pay attention to whether a battery is maintainable or maintenance free. It is clear from the name that in the first case you have to look after the battery yourself: check the electrolyte level and its density. In the second case, the manufacturer, who «buried» the plates and the electrolyte in a sealed structure, makes it clear that the battery is able to take care of itself.
Furthermore, while pondering on which battery is better to buy, do not forget about some remarkable little things that are actually essential. In particular, we are referring to the appearance of a power supply. First of all, check the battery for scratches and cracks, and secondly, make sure that there are no leaks (this is a sign of a used battery).
At the same time, look at the date of manufacture of the battery. In this case the approach is similar to choosing food products, because product service life does not begin with its arrival in the store. It starts from the date when a battery is filled with electrolyte. Preference should be given to batteries that were manufactured less than a year ago.
After having selected a necessary product which complies with all the parameters, do not be too lazy to review the key points again at the checkout. Once again making sure that the case is intact and dry, ask the seller to check the voltage on the multimeter, the operation of the battery with a load plug, as well as to confirm the presence of electrolyte in the battery.
A helpful в tip
Finally, we offer options for how to turn a maintenance free battery into a maintainable one. We are not talking about breaking the integrity of reservoirs, but about proper maintenance of your power source:
- do not discharge the battery to zero, so as not to shorten its service life;
- if you charge a new battery with a small amount of current for a short time, you will contribute to its optimum working condition;
- if you use your car for short distance rides, then you should either charge the battery once a month with stationary equipment, or make occasional trips to the country.
Safe travels!