Attention! Charging the battery produces hydrogen gas, which is highly flammable and explosive. Do not smoke or allow open flames near the battery. Wear eye protection when near the battery while it is being charged. The charger must be switched off before connecting or disconnecting the battery to the charger.
Note. The manufacturer recommends removing the battery from the vehicle in order to charge it, because the gas that is released during this procedure can damage the paintwork. forced (fast) charging with the battery wires connected may damage the electrical system.
11. The best way to recharge a battery that has been discharged to the point where it cannot start the engine is to charge slowly. It is also a good way to maintain the battery level in a car that is mainly used for short trips (short mileage between engine starts). Keeping the battery charged is especially important in winter, when the battery is under more difficult starting conditions and the electrical consumers that draw current from the battery are used more intensively.
12. It is better to use a charger designed for a charging current of 1 A or 2 A. These are the most reliable devices that place the least load on the battery. Also, they are the least expensive. For faster charging, you can use a charger that delivers a higher current, but do not use a charger with a charging current greater than one tenth (0.1) battery capacity in ampere-hours. Fast boost charging, which restores battery efficiency in 1 to 2 hours, is the most severe impact on the battery and may damage the battery in a far from normal condition. This charger should only be used in an emergency.
13. The average time required to charge the battery should be indicated in the instructions that come with the charger. Typically, a slow charger will charge the battery in 12-16 hours.
14. Remove caps from all cells (in the presence of) and cover the openings with a clean cloth to prevent electrolyte splashing. Disconnect the ground wire from the battery and connect the charger wire clamps to the battery terminals (positive clip to positive terminal, negative clip to negative terminal), and then turn on the charger. If the charger has a mode switch, switch it to 12V mode.
15. If you are using a charger with a charging current greater than 2A, check the battery regularly during charging to make sure it does not overheat. If you are using a slow charge charger, after checking the battery regularly for the first couple of hours, you can safely leave it overnight.
16. If the battery has removable cell caps, use a hydrometer to measure the operating 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 came with the hydrometer. The battery can be considered charged when there is no change in the density reading for two hours and the electrolyte in the cells is freely outgassing (bubbling). The density readings in each cell should be very close to each other. If this is not the case, then the state of some cells in the battery is probably not quite normal.
17. Some batteries with sealed top sections have built-in hydrometers on top that indicate the state of charge using the color of the indicator in the hydrometer window. Usually, a bright indicator color indicates that the battery is not fully charged, and a dark indicator indicates that the battery needs to be charged.
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 show 12.6 volts or more after removing the surface charge.
19. For more information about the battery and jump start, see chapter 5 and at the beginning of this Guides.