Warning! When charging the battery, hydrogen gas is formed, which is highly flammable and explosive. Do not smoke or allow open flames near the battery. When near the battery during charging, use eye protection. Before connecting or disconnecting the battery from the charger, turn off the charger.
Note: The manufacturer recommends removing the battery from the vehicle to charge it because the gas released during this procedure may cause damage to the paintwork. Forced (fast) charging with the battery cables connected may cause damage to the electrical system.
11. The best way to restore the charge of a battery that is discharged to the point where it does not start the engine is to slowly charge it. In addition, this is a good way to maintain the charge level of the battery in a car that is used mainly for short trips (short mileage between engine starts). Maintaining battery charge is especially important in winter, when the battery operates under more severe conditions when starting the engine, and electrical consumers that draw current from the battery are used more intensively.
12. It is better to use a charger rated for 1A or 2A charging current. These are the most reliable devices that put the least strain on the battery. They are also the least expensive. For faster charging, you can use a charger that produces a higher current, but do not use a charger with a charging current greater than one tenth (0.1) of the battery's ampere-hour capacity. Rapid boost charging, which restores battery efficiency in 1-2 hours, is the hardest on the battery and can damage a battery that is far from normal. Such charging should only be used in an emergency.
13. The average time it takes to charge the battery should be specified in the instructions that come with the charger. Typically, a slow charger will charge the battery in 12-16 hours.
14. Remove the caps from all the cells (if available) and cover the holes with a clean cloth to prevent electrolyte from splashing out. Disconnect the ground cable from the battery and connect the charger cable clamps to the battery terminals (positive clamp to positive terminal, negative clamp to negative terminal), and then turn on the charger. If the charger has a mode switch, switch it to 12-volt mode.
15. If you are using a charger with a charging current higher than 2A, check the battery regularly during the charging process to make sure it is not overheating. If you are using a slow charger, after checking the battery regularly for the first couple of hours, you can safely leave it overnight.
16. If your battery has removable cell caps, use a hydrometer to measure the specific gravity of the electrolyte every hour during the last few hours of the charge cycle. A hydrometer is inexpensive and can be purchased at an auto parts store. Follow the instructions that come with the hydrometer. The battery is charged when there is no change in the specific gravity reading over a two-hour period and the electrolyte in the cells is freely gassing (bubbling). The specific gravity readings in each cell should be very close to each other. If they are not, some of the cells in the battery may be abnormal.
17. Some batteries with sealed top sections have hydrometers built into the top that indicate the charge status by the color of the indicator in the hydrometer window. Usually, a bright indicator color does not indicate a full charge, and a dark indicator indicates that the battery needs charging.
18. If the battery has a sealed top section and does not have a built-in hydrometer, you can connect a voltmeter to the battery terminals to check the charge level. A fully charged battery should read 12.6 volts or higher after removing the surface charge.
19. For more information on battery and jump starting, see chapter 5 and at the beginning of this Manuals.