- fine-grained sandpaper;
- hydrometer;
- voltmeter;
- charger.
Warning! When servicing the battery, it is necessary to follow safety precautions (see "Safety precautions when servicing and repairing a car").
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 "Battery - Removal and Installation").
4. Check the condition of the battery terminals and wire terminals. If the terminals are covered with a layer of oxides, remove them from the battery terminals (see "Preparing the car for maintenance and repair"). Using sandpaper, clean the battery terminals and wire 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. Disconnect the wire terminal from the negative terminal of the battery (see "Preparing the car for maintenance and repair"). Similarly, we disconnect the terminal from the positive terminal of the battery.
2. Remove the upper battery mounting bar (see "Battery - Removal and Installation") and unscrew the six battery plugs (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. Each float is marked with the minimum density at which it floats.
Note: After adding distilled water, until the battery electrolyte becomes homogeneous, the hydrometer readings will be incorrect. In a single-float hydrometer, the density is determined by the scale on 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 indicated in Table 13.2 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%.
Recommendation: When the battery is discharged more than 50%, charge it.
Advice. If you don't have a hydrometer, you can check the battery's charge level with a voltmeter by measuring the voltage at its terminals. Compare the result with the values in Table 13.1 to determine the battery's charge level.
Table 13.1
| Voltage at battery terminals, V | Degree of charge, % |
| 12,6 | 100 |
| 12,4 | 75 |
| 12,2 | 50 |
| 12,0 | 25 |
3. 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 should be 5.5 A.
4. Charge the battery. We control the process by measuring the density of the electrolyte (see table 13.2). The charging time for a completely discharged battery is at least ten hours at a charging current of 5.5 A.
Table 13.2
|
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 |
5. 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.