In maintenance-free batteries, check the state of charge of the battery through a special inspection hole (photo). The eye also indicates the electrolyte level. Check the condition of the terminals and poles, the presence of corrosion on them. Clean the terminals affected by corrosion, wipe with a solution of soda and rinse with water.
Electrolyte
The electrolyte level on the serviced battery is checked at least monthly. When driving hard or in hot weather, the level should be checked more often. The electrolyte level should reach the split ring (with plug turned out), or match mark (on a transparent body).
On maintenance-free batteries, a special battery is provided for this purpose "peephole". Method of verification using "peephole" set out in the instructions supplied with the battery, or marked on the battery case. As a rule, the green color of the eye indicates a normal state of charge and a normal electrolyte level. A dark eye indicates that the electrolyte level is normal, but the battery is undercharged, and a light eye indicates a drop in the electrolyte level and the need to replace the battery.
Electrolyte Density Check
The density of the electrolyte is checked using an eye built into the battery case.
Method for checking the density of the electrolyte using "peephole" set out in the instructions supplied with the battery, or marked on the battery case. The most accurate density readings are given by measurements with a hydrometer (photo).
Power cables
Periodically check the condition of the battery cables, clean the terminals from plaque. Replace the cable with damaged insulation by selecting it according to its length and section.
Battery charge
It is recommended to charge the battery with a low current, which is approximately 10% of the battery capacity, the battery charging procedure is indicated in the manufacturer's instructions.
Replacement
The new battery must exactly match the one being replaced in terms of capacity and output. After a long period of use of the car, it is allowed to install a new battery with a slightly larger capacity.