2. If a maintenance-free battery is used, it is not possible to check the electrolyte level.
3. Periodically disconnect and clean the battery terminals and wiring. After reinstalling them, lubricate the exposed metal with Vaseline.
4. Check if there is corrosion on the battery terminals and platform. If so, remove the battery, clean the deposit with a wire brush and anti-corrosion liquid, then paint the treated surface.
5. When removing the battery, always check for cracks and leaks.
6. If the battery needs to be replenished frequently, and the case is not broken and the battery does not charge, you need to check the voltage regulator.
7. If the car has a low annual mileage, check the electrolyte density every three months to determine the battery charge state. Use a hydrometer to determine and compare the results with the following table.
| Normal climate | Tropics | |
| Discharged | 1.120 | 1.080 |
| Half charged | 1.200 | 1.160 |
| Fully charged | 1.280 | 1.230 |
8. If you suspect that the battery is in poor condition, first check the specific gravity of the electrolyte in each cell. A difference of 0.040 or more between any cells indicates loss of electrolyte or deterioration of the internal plates.
9. A further test can be done with a discharge meter. The battery should be discharged three times for a maximum of fifteen seconds under an ampere-hour capacity load (at a discharge current of 20 A-hours). Alternatively, connect a voltmeter across the battery terminals and quickly crank the engine with the starter motor with the ignition disconnected (see Section 4), and the headlights, rear window heater and heater blower are on. If the voltmeter shows more than 9.6 volts, the battery is in good condition. If the voltmeter shows less than 9.6 volts, the battery is defective.
10. In winter, when increased power is required from the battery (cold starting and using more electrical equipment), it is a good idea to sometimes have a fully charged battery on hand with a current of 10% of the battery capacity (i.e. 6.3 Amps for a 63 Ah battery).
11. Before connecting the charger, disconnect the battery wiring. Continue charging the battery until the density increases for four hours.
12. Alternatively, a 1.5A charger can be safely used.