- fine-grained sandpaper;
- hydrometer;
- voltmeter;
- Charger.
Warning! When servicing the battery, you must follow the safety rules (see "Safety measures for car maintenance and repair").
Regular battery maintenance
1. We prepare the car for work (see "Preparing the car for maintenance and repair").
2. We wipe the battery case with a cloth moistened with a 10% solution of baking soda or ammonia, and then with clean water.
3. Check the reliability of the battery 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"). With sandpaper, we clean the battery leads and wire terminals to a shine.
5. Check the electrolyte level in each battery. To do this, marks are applied on the battery case "MIN" And "MAX". If the level is below normal, then the hydrometer (or medical syringe) add distilled water to the batteries.
Comment. On a battery that has been in operation for several years, the electrolyte level is poorly visible through the case wall. In this case, you can check the level through the filler holes of the batteries. The electrolyte should completely cover the battery separators and slightly not reach the lower edges of the filler 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, disconnect the terminal from the positive terminal of the battery.
2. Remove the top battery mount (see "Battery - removal and installation") and turn out six battery plugs (it is convenient to do it with a coin).
3. Using a hydrometer bulb, we select part of the electrolyte into the flask of the device and, without removing the nose of the flask from the filler 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.
Comment. After topping up with distilled water, until the battery electrolyte becomes homogeneous, the hydrometer readings will be incorrect. In a hydrometer with one float, the density is determined by a scale printed 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 operation of the car.
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 discharged more than 50%, charge the battery.
Advice. In the absence of a hydrometer, the degree of charge of the battery can be checked with a voltmeter by measuring the voltage at its terminals. By comparing the result with the values given in Table 13.1, determine the battery charge.
Table 13.1
| Voltage at battery terminals, V | Degree of charge, % |
| 12,6 | 100 |
| 12,4 | 75 |
| 12,2 | 50 |
| 12,0 | 25 |
3. We connect the charger to the terminals of the battery, observing the polarity, and only after that we turn on the charger to the mains. The charging current should not exceed 10% of the battery capacity in amperes, that is, the maximum charge current should be 5.5 A.
4. We charge the battery. The process is controlled by measuring the density of the electrolyte (see table. 13.2). The charging time of a completely discharged battery is at least ten hours at a charging current of 5.5 A.
Table 13.2
|
Climatic operating conditions |
Electrolyte density (at +25°C), g/cm³ |
|||
|
poured into the battery when refueling |
in a battery in which the state of charge of the 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: |
||||
|
winter |
1,29 |
1,31 |
1,27 |
1,23 |
|
in summer |
1,25 |
1,27 |
1,23 |
1,19 |
5. We stop charging the battery after all its batteries begin to release abundant gas: first, disconnect the charger from the mains and only after that disconnect the wires from the battery terminals.