—
Serviced. Serviceable are only classic lead-acid batteries (see "Type"): they are easy to distinguish even externally — by the presence of removable plugs that give access to internal containers with electrolyte. The latter is a mixture of sulfuric acid and water, and with each charge, some of this water "boils away" (decomposes into oxygen and hydrogen and volatilizes). This is especially intense when overcharging or charging at high voltage. Battery maintenance consists in periodically replenishing the water in the electrolyte — without this, lowering its level leads to damage to the plates due to contact with air, which irreparably degrades battery performance. On average, maintenance should be carried out 1-2 times a year (15-20K kilometers for a passenger car) and these terms usually coincide with the terms of scheduled maintenance. However, this value may vary depending on the features 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, because. even a relatively small amount of foreign matter can damage the wafers.
—
Unattended. As the name suggests, these batteries do not require the maintenance described above; this is achieved in a number of ways, in particular by filling the electrolyte with a margin for the entire service life or using a gel (se
...e "Type"). With clear 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, they tolerate cold and long periods of inactivity worse.Has
a charge indicator on the battery.
Such an indicator displays the current charge level and allows you to generally assess the state of the battery literally at a glance, without additional actions and diagnostic equipment. In some models of serviceable batteries, the indicator can signal not only the need for charging, but also the need to add water to the electrolyte (for more details, see "Maintenance").
