The term "unattended", (or more precisely, low-maintenance) the battery indicates that the electrolyte loss caused by electrolysis and water evaporation is reduced in this battery and there is no need to frequently add distilled water to it.
The battery case is made of translucent plastic, which allows you to check the electrolyte level in the battery visually. If distilled water has to be added to the electrolyte more than once a year, you should check the voltage regulator for serviceability.
During continuous operation of a serviceable vehicle, additional battery charging is not required. If the vehicle is used for a long time (more than a few weeks), especially in the cold season, if the battery has not been used, it may need to be recharged before starting the engine.
Battery life depends on many factors (conditions and intensity of operation, the technical condition of the vehicle's electrical equipment, etc.) and can reach six years or more. When choosing a new battery, you need to pay attention to the location of its positive and negative terminals. The terminals of the battery intended for some foreign-made cars have opposite polarity.
There are batteries on sale that are ready for use and so-called dry-charged. The former can be installed on the car immediately and put into operation, while the latter must first be filled with electrolyte and recharged if necessary.
Helpful advice: After installing a battery on a car, ready for use, check the density of the electrolyte and recharge it if necessary.
[The original source is published on the website: VAZBOOK.ru]