Control And Power System Operational Checks

Battery Load Test

1. Turn the range switch on the multimeter to read battery voltage.

2. Connect the battery.

Battery Voltage Test (1) Positive cable connection. (2) Negative cable connection

3. Connect the multimeter leads between positive (+) cable connection (1) and negative (-) cable connection (2).

4. In a safe area, operate the hydraulic system (hold tilt lever to maximum position momentarily) while reading the voltage on the multimeter.

5. If the reading is less than 33.1 volts for 36V trucks, 44.2 volts for 42V trucks, 66.2 volts for 72V trucks or 73.6 volts for 80V trucks, the battery needs to be charged or repaired before continuing to troubleshoot.

Cell Voltage Test

With the truck powered up and the hydraulic pump motor running, measure the voltage at each cell. Normal voltage should be between 1.95V and 2.12V per cell. If the voltage on each cell is below 1.95, the battery must be charged or repaired before continuing to troubleshoot.

NOTE: The indication between cells should not differ more than 0.05 volts. If it does, the battery must have an equalizing charge or be repaired.

Hydrometer Test

Test each cell of the battery with the 5P0957 or 5P3514 Battery Tester Group. If the specific gravity indicated is below 1.140, the battery must be charged. The battery is fully charged if the indication is 1.265 to 1.285.

NOTE: The indication between cells should not differ more than .020. If it does, the battery must have an equalizing charge or be repaired.

Battery Maintenance

NOTE: It is important that all batteries be charged and maintained according to the battery manufacturer’s instructions.

The care and maintenance of batteries is most important to maximum battery life and efficient truck operation. Periodic inspection and service will increase the life of batteries. Special attention should be given to the rules that follow:

1. Keep the batteries clean at all times. Cleaning will prevent corrosion, current leakage and shorts to chassis. Tighten all vent plugs, wash the battery with water and a brush, then dry with an air hose. It may be necessary to use a baking soda solution if water alone will not clean the top of the battery.

2. Add enough water to cover the plates before charging. This will ensure the proper chemical reaction over the entire plate surface. After charging is complete, add water until it is about 12.7 mm (.50 in) above the plates. Use distilled water or water that has tested free from minerals.

3. Charge the battery correctly. A battery should be discharged to 80% of its capacity then fully recharged. It should cool four to eight hours to allow the voltage to stabilize before being put back in use. The battery should have an equalizing charge (an extra three or four hour charge at a low finish rate) once a month to make sure all cells are in a fully charged condition.

Properly charged batteries should be identified to prevent low batteries from being installed in trucks.

4. Operation with a low battery must be prevented. Low battery operation may damage the battery and will cause higher than normal current in the electrical system. High current draw due to a low battery will damage contactor tips and shorten motor brush life.