General description
1. During normal use, the battery should not require charging from an external source. If regular recharging is required, there may be a fault in the battery or in the charging system
2. If the vehicle has not been used for a long period (more than thirty days) the battery can lose approximately 1% of its energy per week. This is only true for a disconnected battery; if the battery is left connected to the vehicle's electrical system, it will discharge faster due to the clock and car radio (memory) circuits. To prevent this, always disconnect the negative cable from the battery whenever the vehicle is not going to be used for an extended period. To keep the battery fully charged, it should be regularly recharged every six weeks. This is especially important for "maintenance-free" batteries, which lose energy capacity as a result of being completely discharged.
Examination
3. Leave the battery disconnected for at least two hours, then measure the voltage (no load). connecting a sensitive voltmeter to the battery terminals. Compare the result obtained with the following table:
| Voltmeter readings | State of charge |
| 10.50 B | Completely discharged |
| 12.30 B | Charged to 50% |
| 12.48 B | Charged to 75% |
| 12.66 V or more | Fully charged |
4. Checking the electrolyte level is described in Section 1. If frequent refilling is required and there are no cracks in the battery case, and the battery is not constantly fully charged; the voltage regulator needs to be checked.
5. If the car has a very low annual mileage, it is recommended to check the density of the electrolyte every three months to determine the state of charge of the battery. To check, use a hydrometer and compare the results with the following table:
| Normal climate | Tropics | |
| Discharged | 1.720 | 1.080 |
| Half charged | 1.200 | 1.160 |
| Fully charged | 1.280 | 1.230 |
6. If the battery condition is not exactly known, check the density of the electrolyte in each cell. The difference is 0.040 (or more) between any cells indicates loss of electrolyte or wear of the internal plates.
7. Next, check with a voltmeter. Connect the device to the battery terminals and turn the starter, grounding the high-voltage ignition coil wiring with an auxiliary wire and turning on the headlights, rear window heater and heater blower. If the voltmeter readings do not fall below 9.5 V, the battery is OK. If the voltage is below 9.5 V, the battery is faulty.
Charger
8. In winter, when more energy is required from the battery (cold engine starting and switching on a large amount of electrical equipment), it is recommended to recharge it from an external power source. The battery charging rate depends on its code; the best way is to use a charger overnight with a charging current of 1.5A. Fast charging the battery for 1-2 hours is not recommended as it may cause serious damage to the battery plates due to overheating.
9. Ideally, the battery should be removed from the vehicle before charging.
Warning: Hydrogen gas will be released from the battery during charging and for approximately 15 minutes after charging (flammable): therefore, make sure that there is no open fire near the battery, as there may be an explosion.
10. Continue charging the battery until all cells are vigorously gassing and the no-load voltage has not increased for four hours. When charging is complete, turn off the charger and only then disconnect the cables from the battery.