Checking the battery

The condition of the battery is checked by measuring the voltage between the battery poles with a voltmeter.

Clean the outside of the battery.

Before testing, the battery must not be charged for at least six hours, including by rotating the engine. Otherwise, turn on the main headlight for 30 seconds before checking.

Turn off the headlights, as well as all other electrical consumers, and pause for 5 minutes.



Connect a voltmeter to the battery terminals and measure the voltage.

Evaluation of measurements

12.7V or higher = battery in good condition.

12.6 V = normal.

12.4V or below = Battery is in poor condition, please charge or replace it.

Battery test under load

Connect a voltmeter to the battery terminals.

Start the engine and read the voltmeter reading.

During the starting process with a fully charged battery, the voltage must not fall below 10 V (at an electrolyte temperature of about +20°С).

If the voltage immediately drops and the cells show different electrolyte densities, then the battery is faulty.

Electrolyte Density Check

As a result of measuring the battery voltage and electrolyte density, an accurate conclusion can be made about the condition of the battery. A densimeter is used to check the density of the electrolyte. The higher the density of the electrolyte (absorbed acid concentration), the deeper the densimeter float sinks. On the scale, you can determine the density of the electrolyte in g / ml or degrees Baume (+ °Be). The following values are possible:

State of charge	+ Be	g/ml
Battery low	16	1,15
Battery is half charged	24	1,22
Battery well charged	30	1,26

Check all battery cells one by one. They must have the same electrolyte density (without connected consumers). Otherwise, the battery is defective.

Battery test under load

Connect a voltmeter to the battery terminals.

Note! If the battery voltage (without connected electrical consumers) is less than 12.0 V, the battery is low and should be recharged.

Start the engine and determine the voltage value.

During start with a charged battery, the voltage should not fall below 10 V (at an electrolyte temperature of about +20°C).

If the voltage immediately drops, and the cells show different concentrations of acid, then it can be concluded that the battery is faulty.