Trial
1. If the vehicle has a low annual mileage, check the electrolyte density every three months to determine the condition of the battery. Measure the density of the electrolyte with a hydrometer and compare the results with the following table. Please note that the given electrolyte densities are given for a temperature of 15°C. For every 10°C below 15°C subtract 0.007 and for every 10°C above 15°C add 0.007.
Ambient temperature | Above 25°C | Below 25°C |
Fully charged | 1.210 - 1.230 | 1.270 - 1.290 |
70% charged | 1.210 - 1.230 | 1.230 - 1.250 |
Discharged | 1.050 - 1.070 | 1.110 - 1.130 |
2. If the condition of the battery is not exactly known, check the density of the electrolyte in each cell. Difference in 0.040 (or more) between any cells indicates a loss of electrolyte or worn internal plates.
3. If the difference in electrolyte density in different cells is 0.040 (or more), the battery must be replaced. If this difference is below 0.040, but the battery is discharged, it should be recharged as described later in this Section.
Maintenance free battery
1. In cases where a sealed, maintenance-free battery is installed, refilling and checking the electrolyte density in each cell is not possible. The condition of the battery can only be checked with an appropriate indicator or voltmeter.
2. The Delco maintenance-free battery has a built-in charge indicator. The indicator is located in the upper wall of the battery case and the degree of charge of the battery can be determined by its color. If the indicator is green, the battery is fully charged. As the battery discharges, the indicator becomes darker and eventually black, which means that the battery needs to be charged as described later in this Section. If the indicator turns bright/yellow, the electrolyte level in the battery is too low and the battery needs to be replaced. Do not attempt to charge the battery or start the engine during this time.
3. To test the battery with a voltmeter, connect the voltmeter to the battery terminals. This measurement will only be accurate if the battery has not been charged within the previous six hours. If this condition has been violated, turn on the headlights and leave them on for 30 seconds. After turning off the headlights, wait 4 to 5 minutes and take a measurement. All other electrical circuits must be turned off. Make sure all doors are well closed.
4. If the measured voltage is less than 12.2 Volts, then the battery is completely discharged, while a voltage of 12.2 - 12.4 Volts indicates its partial discharge.
5. If the battery needs to be charged, remove it from the vehicle (Chapter Removing and installing the battery) and charge as described later in this Section.
Charger
Standard Batteries
Note. The following information is given as a general guide. Always refer to the manufacturer's recommendations before charging the battery.
1. The battery is charged with a current of 3.5 - 4 A. Continue charging the battery with this current until an increase in electrolyte density is observed. After four hours have elapsed since the last increase in density, you can stop charging the battery.
2. Alternatively, charging the battery at 1.5A can safely be done overnight.
3. Charging too fast to fully recharge the battery within 1 to 2 hours is not recommended as it may cause serious damage to the battery plates due to overheating.
4. When charging the battery, make sure that the temperature of the electrolyte never exceeds 37.8°C.
Maintenance free battery
Note. The following information is given as a general guide. Always refer to the manufacturer's recommendations before charging the battery.
Installation
1. Fully charging this type of battery takes significantly longer (up to three days with a significant discharge).
2. For charging, you need a charger that outputs constant voltage. After connecting, the device must be set to a voltage of 13.9-14.9 Volts at a current below 25 A. With this charging method, the battery will be usable in three hours, delivering a voltage of 12.5 Volts. Such a charge time is real if the battery is only partially discharged, a full charge requires much more time.
3. If the battery is being charged from a fully discharged state (voltage below 12.2 volts), charge the service station with charging, as this process requires constant supervision of a specialist.