Examination
Standard batteries and low maintenance batteries
1. If the car has a low annual mileage, it is recommended to check the electrolyte density every three months to determine the state of charge of the battery. Use a hydrometer to measure the density of the electrolyte in sections and compare the results with the table below. Keep in mind that density values are given for an electrolyte temperature of 15°C; for every 10°C below 15°C subtract 0.007. For every 10°C above 15°C add 0.007.
Above 25°C/ Below 25°C
Fully charged 1210...1230/ 1270...1290
70% charged 1.170...1.190/ 1230...1250
Discharged 1.050...1070/ 1.110...1.130
2. If the condition of the battery is suspicious, first check the density of the electrolyte in each section. A difference of 0.040 or more between any two sections indicates a lack of electrolyte or a deterioration in the condition of the internal plates.
3. If the density difference is 0.040 or more, the battery should be replaced. If the difference between the sections is satisfactory, but the battery is low, it should be recharged as described in this paragraph below.
Maintenance free batteries
4. When installed «sealed for life» maintenance-free battery, topping up and checking the electrolyte density in each section is not possible. Therefore, the condition of the battery can only be checked with a battery status indicator or a voltmeter.
5. Some models can be equipped with a maintenance-free alternator «Delco» with built-in charge level indicator. The indicator is located on top of the battery case and shows the status of the battery by changing its color. If the indicator is green, the battery charge status is good. If the indicator darkens and eventually turns black, the battery needs to be recharged as described later in this paragraph. If the indicator turns blue, then the electrolyte level in the battery has become too low for further use of the battery. This battery will need to be replaced.
Warning. Do not attempt to charge or load the battery, or start the engine with an external battery, when the indicator is clear or amber.
6. When checking the battery with a voltmeter, connect the voltmeter to the battery terminals, take a reading and compare the result with the value given in «Specifications». The test will only be accurate if the battery has not been charged within the previous six hours. If this is not the case, turn on the headlights for 30 seconds before checking the battery and wait 4-5 minutes after turning off the headlights. All other electrical circuits must be turned off, so make sure all doors, including the tailgate, are fully closed before starting the test.
7. If the voltmeter reading is less than 12.2V, the battery is low. A reading of 12.2-12.4 V indicates that the battery is partially discharged.
8. If the battery requires recharging, remove it from the vehicle (paragraph 4) and charge as described later in this paragraph.
Charger
Note. The following information is provided as a guide only. Be sure to read the manufacturer's recommendations before charging the battery (often listed on the label affixed to the battery).
Standard and low maintenance batteries
9. Charge the battery with a current of 3.5 to 4.0 A until then. until no increase in electrolyte density is observed for four hours.
10. Alternatively, you can charge slowly with 1.5A current, and the charger can safely be left on overnight.
11. Too fast («forced») charging capable of restoring the battery within 1-2 hours is not recommended as it may cause serious damage to the battery plates due to overheating.
12. When charging the battery, keep in mind that the temperature of the electrolyte should never rise above 40°C.
Maintenance free batteries
13. This type of battery takes much longer to fully charge than a standard battery. The actual time depends on the level of discharge, it may take up to three days.
14. Requires a constant voltage charger capable of generating 13.9-14.9V when connected, with charging current below 25A. After using this method, the battery should remain «active» for three hours, giving a voltage of 12.5 V, but this refers to a partially discharged battery. As already mentioned, a full charge may take significantly longer.
15. If the battery needs to be charged from a fully discharged state (voltage less than 12.2 V), take the battery to be recharged by your dealer or other automotive electrician, as more charging current is required and constant supervision is required during the charging process.