Warning: do not short-circuit the contacts of the battery, as this will heat it up and may crack. Do not use open fire near the battery. The battery electrolyte is very caustic and should not come into contact with eyes, skin or clothing. If this does happen, the electrolyte should be washed off with plenty of water.
Before charging, you need to disconnect the wires from the battery. The negative wire is disconnected first.
A frozen battery must be thawed before charging. A charged battery freezes at a temperature of about -65°C, a half-charged battery freezes at a temperature of about -30°C, and a discharged battery freezes at a temperature of about -12°C.
A battery that has been in a discharged state for a long time cannot be fully charged or charged at all with a conventional charger. In this case, an electronic charger must be used, since with a low charging current, the battery does not heat up as much.
Before charging, you need to check the battery voltage when it is disconnected.
Remove the plugs from the battery and place them over the holes to prevent electrolyte splashes from getting on the paintwork during the charging process when gases are released from the battery.
Charge the battery only in a well-ventilated area. If the battery is charged in a car, open the trunk.
During normal charging, the charging current is about 10% of the battery capacity (for a 50 Ah battery - about 5 A). As a rule, the charging time is about 10 hours.
Connect the charger wires to the battery, observing the polarity of the connection.
The electrolyte temperature during charging should not exceed + 55°C; if necessary, stop charging or reduce the charging current.
Continue charging until all the cans begin to actively release gases (the battery "boils") and during the last three measurements, separated by 1-hour intervals, the electrolyte density and voltage do not increase.
Check the electrolyte level after charging and add distilled water if necessary.
Check the density of the electrolyte. If the density of the electrolyte in one of the cans is very different from the others (for example, in 5 cans the density is 1.26 g/ml, and in one can it is 1.18 g/ml), then the battery is faulty and needs to be replaced.
Give the AB 20 minutes for the gases to stop escaping, then screw the caps on the jars.
Caution: The engine must not be operated with the battery disconnected, otherwise the electrical system components will be damaged.