Check the electrolyte level and density every 15,000 km.
Regularly clean the battery from dust and dirt. If the top cover is cracked or bulging, replace the battery.
The electrolyte must be transparent. A brown shade indicates shedding of the active mass of the plates - the battery needs to be changed.
Checking the electrolyte level
Warning: During operation, the electrolyte level gradually decreases due to the evaporation of water contained in it. To restore the level, add only distilled water to the battery.
If the battery has a translucent case, the electrolyte level is determined visually: it must be between the marks «MIN» and «MAX» on the side of the battery.
If the battery has an opaque case, unscrew the six plugs on the cover.
Check the electrolyte level in the first battery cell by inserting a glass tube (it is sold with a hydrometer) into the hole until it stops in the safety net; then, pinching the tube with your finger...
...take it out without releasing your finger. The electrolyte level should be 10-15 mm.
Insert the tube into the hole and release your finger to drain the electrolyte. In the same way, check the level in the other banks of the battery. If any of the jars is low, add distilled water to the jar to the recommended level.
Electrolyte Density Check
Warning: When checking the density, be careful: the electrolyte contains sulfuric acid! Drops of electrolyte that have fallen on parts of the car or on open areas of the body, immediately rinse with plenty of water.
The density of the electrolyte can only be measured two hours after adjusting its level: the water must mix with the electrolyte. To check the density, insert the hydrometer into the hole until it stops in the safety net and select the electrolyte with a pear so that the hydrometer float floats.
The division on the float, located at the level of the electrolyte, shows its density. Keep in mind that the density depends on the temperature of the electrolyte, so make a correction to the measurement result (tab. 4). By density, you can judge the degree of battery discharge (tab. 5). If the density is below normal or differs in banks by more than 0.02 g/cm3, need to recharge the battery.
Table 4. Correction to hydrometer readings depending on electrolyte temperature
Electrolyte temperature,°С | Correction, g/cm3 |
-40 to -26 | -0,04 |
-25 to -11 | -0,03 |
-10 to +4 | -0,02 |
+5 to +19 | -0,01 |
+20 to +30 | 0,00 |
+31 to +45 | +0,01 |
Drain the electrolyte from the hydrometer into a battery can.
Table 5. Electrolyte density at 25°С, g/cm3
climatic region (average monthly air temperature in January,°C) | Season | Fully charged battery | Battery low | |
by 25% | by 50% | |||
Very cold (-50 to -30) | Winter Summer | 1,30 1,28 | 1,26 1,24 | 1,22 1,20 |
Cold | All year round | 1,28 | 1,24 | 1,20 |
Moderate | All year round | 1,28 | 1,24 | 1,20 |
warm humid (from 0 to +4) | All year round | 1,23 | 1,19 | 1,15 |
hot dry (-15 to +4) | All year round | 1,23 | 1,19 | 1,15 |