Electrolyte Density Check
1. Checking the density of the electrolyte together with measuring the voltage allows you to make an accurate conclusion about the state of charge of the battery. For verification, a hydrometer is used, which can be purchased inexpensively in specialized trade. The greater the density of the electrolyte, the more the float floats. On the scale, you can read the density values in units of a specific weight (g/ml) or degrees Baume (°Be). The following values must be reached (at an electrolyte temperature of +20°C).
Charge degree | Gas engine | diesel engine | ||
+°Be | g/ml | +°Be | g/ml | |
discharged | 8 | 1,06 | 11 | 1,08 |
half charged | 20 | 1,16 | 22 | 1,18 |
well charged | 30 | 1,26 | 32 | 1,28 |
2. Check each cell of the battery in turn, the electrolyte in all banks must have the same density (the maximum difference is 0.04 g/ml. Otherwise, you can conclude that the battery is faulty.
Battery test under load
1. Connect a voltmeter to the battery terminals.
Note. If the battery voltage (without connected consumers) below 12V, the battery is low and needs to be recharged.
2. Start the engine and read the voltage value.
3. When starting, the voltage of the charged battery should not fall below 8V (at an electrolyte temperature of +20°С).
4. If the voltage immediately drops and different densities are detected in the banks, this indicates a battery malfunction.
5. The total voltage can be measured with a battery tester. Follow instructions for use.
Validation values
Ah capacity | Test current A | Load current A | Minimum voltage after 5-10 seconds at a temperature of 0 to +204°C |
54 | 265 | 200 | 9.4 V |
64 | 380 | 300 | 9.0V |
88 | 395 | 300 | 9.5 V |
Attention! If this measurement (within 10 sec) the total voltage falls below the indicated value, the battery is either discharged or defective.