Alternative Test Method
Follow the steps below:
1. Checking the density of the acid
The density of the acid can be measured using an electrolyte gauge or a refractometer on the battery at room temperature.
Measure the density in all the cells. Check the following:
- If the density is above 1.225 g/cm3 in each cell and the difference in density between the cells is less than 0.03 g/cm3 , the battery must be tested for load. See point 4 below, Load check
- If the density is below 1.225 g/cm3 in each cell and the difference in density between the cells is less than 0.03 g/cm3 , the battery must be charged. See BATTERY, CHARGING
- If the density in two adjacent cells is considerably lower than in other cell (i. e. if the difference is greater than 0.03 g/cm3 , there is probably leakage between the two cells. Discard the battery
- If the density is markedly lower in only one cell, the fault is probably a short-circuit. Check the battery acid for discoloration. Discard the battery.
2. Checking the stand-by voltage
Check the stand-by voltage as follows:
- Disconnect the cable from the battery negative terminal
- Leave the battery disconnected for at least 2 hours
- Measure the stand-by voltage using a digital multimeter. The battery must be recharged immediately if the stand-by voltage is lower than 12.45 V. For information about charging, see BATTERY, CHARGING
- If the car has not been delivered to a customer - update the Battery Maintenance Card, as shown
- Connect the battery negative terminal.
3. Charging
If the battery is not charged, it must be charged according to BATTERY, CHARGING .
Check that the battery takes the charge.
- If the charge is OK, the battery must be load tested. See point 4 below, Load check
- The battery may be sulfated if it does not charge. Sulfating means that the battery is damaged due to insufficient charge. Discard the battery.
4. Load check
During a load test, the load current must rise to at least 3 times the battery capacity in amperes (A).
For example: A battery with a capacity of 60 Ah must be loaded with a current of 180 A (= 3 x 60).
Read off the battery voltage after approximately 15 seconds. The voltage must then be 9.6 V. If this voltage is not reached there may be an open-circuit or a short-circuit in the battery.
- An open-circuit can be identified, for example, by the voltage dropping rapidly towards 0 V when the battery is loaded, or if the voltmeter does not give a reading when connected to the battery. Discard the battery if there is an open-circuit
- A short-circuit is most often evident under load when the short-circuited cell or cells begin to boil. Discard the battery if there is an short-circuit.
5. Self-discharge
If the battery has been checked according to points 1-4 above, but is not showing signs of the above faults, set the battery to self-discharge to check that the self-discharge is normal.
If the battery self-discharges abnormally and does not retain a charge for more than a couple of days, this may be a sign of a potential short-circuit. Discard the battery.