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Maintainable. Only classic lead-acid batteries (see "Type") can be serviced: they are easy to distinguish even externally — by the presence of removable plugs that provide access to internal containers with electrolyte. The latter is a mixture of sulfuric acid with water, and with each charge, some of this water "boils away" (decomposes into oxygen and hydrogen and evaporates). This happens especially intensively during overcharging or charging at high voltage. Battery maintenance consists of periodically replenishing the water reserves in the electrolyte — without this, a decrease in its level leads to damage to the plates due to contact with air, which irreparably worsens the battery's characteristics. On average, maintenance should be carried out 1-2 times a year (15-20 thousand km of mileage for a passenger car) and these periods usually coincide with the terms of scheduled maintenance. However, this value may vary depending on the characteristics of both the battery itself and its operation; More detailed information is usually contained in the instructions for specific models. "Refilling" should be done exclusively with distilled water, since even a relatively small amount of foreign impurities can damage the plates.
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Maintenance free. As the name suggests, such batteries do not require the maintenance described above; this is achieved in a number of ways, in particular by filling the elect
...rolyte with a reserve for the entire service life or using gel (see "Type"). With obvious advantages due to ease of use, maintenance-free batteries at the same time have one drawback: they are much more sensitive to deep discharge (capacity decreases), and, accordingly, tolerate cold and long periods of downtime worse.In this case, polarity refers to the location of the terminals on the battery. Traditionally, it is named according to the location of the "+" terminal when looking at the battery from the front (or, in the case of side terminals, from the side closest to which they are located).
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+ left. In relation to passenger cars, such polarity in the CIS countries is often called "direct" or "ours". At the same time, in trucks (see "Purpose") the situation is the opposite - the left "plus" is the European standard.
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+ right. In passenger cars, the right "plus" is typical mainly for European models, for which this polarity in the CIS countries received the unofficial name "euro" or "reverse" (as opposed to the domestic "direct"). In batteries for trucks, everything is the other way around.
— + right/ + left. This marking means that this battery model is available with both right and left “plus” (see above), and you can choose the option depending on the car model.
Note that the above division into “direct” and “reverse” polarity is not absolute, and in any case, before purchasing a battery in your car, this parameter should be clarified separately.