The condition of the battery is checked by measuring the density of the electrolyte with a densimeter.
The measured density of the electrolyte is compared with the values in Table 8.1, which allows you to assess the condition of the battery.
Table 8.1. Battery charge level depending on electrolyte density
The density of the electrolyte in all cans should be the same and differ from each other by no more than ±0.02 g/cm³. If the density of the electrolyte in neighboring cans differs sharply, then the battery has a short circuit and is faulty.
[This note was copied from the resource: renaultbook.ru]
Inspect the battery and make sure of the following:
- there are no cracks or signs of damage on the battery case or cover;
- there are no traces of dirt on the top of the battery;
- the terminals are in good condition;
- there are no salt deposits on the terminals (sulfation).
Check the tightness of the wire clamp nuts on the terminals. Poor contact between the wire tips and terminals may prevent the engine from starting and reduce the efficiency of charging the battery. In addition, if the contact is poor, sparking occurs, which may lead to an explosion of the battery.
Clean and lubricate with neutral grease (technical vaseline) battery terminals and wire ends.
Check the electrolyte level by unscrewing the plugs on the top of the battery.
On batteries with removable caps, remove the cap by hand or with a tool (for example, a hard spatula).
Check the electrolyte level in all cans; it should be approximately 1.5 cm above the separators.
If necessary, add distilled water to the battery.
Note: The translucent housing of some batteries allows you to monitor the electrolyte level.
Never add electrolyte, acid or other liquids to the battery.