Note: There are maintenance-free batteries with a sealed case on sale. Such batteries do not have openings for adding water and checking the density of the electrolyte.
To complete the work you will need:
- fine-grained sandpaper;
- voltmeter;
- hydrometer;
- charger.
Warning! When servicing the battery, it is necessary to observe safety regulations and work in rubber gloves.
Regular battery maintenance
1. Prepare the car for work (see "Preparing the car for maintenance and repair").
2. Wipe the battery case with a cloth soaked in a 10% solution of baking soda or ammonia, and then with clean water.
3. Check the reliability of the battery fastening on the car (see above, "Battery - Removal and Installation").
4. Check the condition of the battery terminals and power cable terminals. If the terminals are covered with a layer of oxides, remove the terminals from the battery terminals. Use sandpaper to clean the battery terminals and cable terminals until they shine.
5. Check the electrolyte level in each battery, for this purpose the battery case is marked with "MIN" and "MAX". If the level is below the norm, use a hydrometer (or a medical syringe) we add distilled water to the batteries.
Note: On a battery that has been in operation for several years, the electrolyte level is poorly visible through the case wall. In this case, the level can be checked through the battery filler holes. The electrolyte should completely cover the battery separators and slightly fall short of the lower edges of the filler hole wells.
Checking and charging
1. Remove the battery from the car or disconnect the wire terminals from the battery terminals (see above).
2. Unscrew the battery caps (it's convenient to do this with a coin).
3. Using the bulb of the hydrometer, we collect some of the electrolyte into the flask of the device and, without removing the spout of the flask from the filling hole of the battery, we determine the density of the electrolyte in each battery using the floats. The minimum density at which it floats is written on each float.
Note: After adding distilled water, until the solution in the battery is completely mixed, the hydrometer readings will be incorrect. In a hydrometer with one float, the density is determined by the scale applied to the float and depends on the depth of its immersion.
The density of the electrolyte in a fully charged battery should be close to that specified in Table 13.4.1. in accordance with the climatic zone of vehicle operation.
When taking hydrometer readings, it is necessary to take into account the temperature correction. When the electrolyte temperature decreases by one degree, the battery capacity decreases by 1-2%.
Table 13.4.1
|
Climatic conditions of operation |
Electrolyte density (at +25°C), g/cm³ |
|||
|
poured into the battery when refueling |
in a battery, which has a state of charge of batteries |
|||
|
100% |
75% |
50% |
||
|
Hot climate (all year round) |
1,23 |
1,25 |
1,21 |
1,17 |
|
Temperate climate (all year round) |
1,25 |
1,27 |
1,23 |
1,19 |
|
Cold climate (all year round) |
1,27 |
1,29 |
1,25 |
1,21 |
|
Very cold: |
||||
|
in winter |
1,29 |
1,31 |
1,27 |
1,23 |
|
in summer |
1,25 |
1,27 |
1,23 |
1,19 |
Note: If you don't have a hydrometer, you can check the battery charge level with a voltmeter by measuring the voltage at the battery terminals. By comparing the result with the values in the table, determine the battery's contamination.
Table
13.4.2|
Voltage at battery terminals, V |
Degree of charge, % |
|
12,6 |
100 |
|
12,4 |
75 |
|
12,2 |
50 |
|
12,0 |
25 |
Recommendation: A battery that is discharged by 50% or more must be charged.
The information is published on the website: VAZBOOK
4. Connect the charger to the battery terminals, observing the polarity, and only then plug the charger into the power grid. The charging current should not exceed 10% of the battery capacity in amperes, i.e. the maximum charging current is 5.5 A.
5. Charge the battery. We control the process by measuring the density of the electrolyte. The charging time of a completely discharged battery is at least ten hours at a charging current of 5.5 A.
6. Stop charging the battery after all of its batteries begin to emit gas: first, disconnect the charger from the power supply, and only then disconnect the wires from the battery terminals.
7. Screw the plugs back into place.
8. Place the power cable terminals on the battery terminals. Using a spanner by 10 mm we tighten the terminal mounting bolts and apply a thin protective layer of plastic grease to the terminals and battery posts.